CHAPTER IX PROPELLING MACHINERY

No aspect of old naval¹ warfare² is so difficult for the modern reader to visualize³, perhaps, as that which displays the essential weakness of the sailing warship⁴: its impotence in a calm. It was a creature requiring for its activities two elements, air and water. Ruffle⁵ the sea with a breeze, and the sailing ship had power of motion towards most of the points of the compass; withdraw the winds, and she lay glued to the smooth water or rolling dangerously in the heavy swell⁶, without power either of turning or translation. For centuries this weakness told heavily against her and in favour of the oar⁷-propelled vessel⁸, particularly in certain latitudes⁹. Through many years, indeed, the two types held ascendancy¹⁰ each in its own waters; in the smooth stretches of the Mediterranean¹¹ the oar-driven galley¹², light, swift, and using its sharp ram¹³ or bow-cannon¹⁴ as chief means of offence or defence, was a deadly danger to the becalmed sailing ship; in the rougher north Atlantic the sailing ship, strong, heavy, capacious, and armed for attack and defence only along its sides, proved far too fast and powerful for the oar-driven rival. Progress—increase of size, improvement in artillery¹⁵, the development of the science of navigation—favoured the sailing ship, so that there came at last the day when, even in the Mediterranean, she attained¹⁶ ascendancy over the galley. But always there was this inherent weakness: in a dead calm the sailing ship lay open to attack from a quarter where her defence lay bare. Ninety-nine times out of a hundred, perhaps, she could move sufficiently¹⁷ to beat off her attacker by bringing her broadsides to bear. The hundredth, she lay at the mercy of her adversary¹⁸, who could, by choosing his range and quarter of attack, make her temporary inferiority the occasion of defeat. For this military reason many attempts were made to supplement sails with oars¹⁹. But oars and sails were incompatible²⁰.211 They were often, seen together in early times, but with progress the use of one became more and more irreconcilable²¹ with the use of the other. The Tudor galleasse, though possessing in our northern waters many advantages over the galley type, had the defects inherent in the compromise, and gave place in a short time to the high-charged “great ship” propelled by sails alone. The sailing ship was by that time strong and powerful enough to risk the one-in-a-hundred chance of being attacked by oared²² galleys²³ in a stark²⁴ calm. It was only when the first steam vessels²⁵ plied²⁶ English waters that the old weakness became apparent again. It was then seriously urged that the ship-of-the-line should carry oars once more, against the attack of small steamers converging²⁷ on her from a weakly defended quarter.

SHIP AND GALLEY

(From Tartagliá’s Arte of Shooting, English Ed., A.D. 1588.)

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The oar was in many ways an objectionable form of power. It was very vulnerable, its presence made man?uvring at212 close quarters risky²⁸ and difficult; and apart from the necessity, on which the galley service was based, of a large supply of slave-labour for working them, oars and the rowers absorbed a large proportion of the available inboard space, to the detriment³⁰ both of artillery and merchandise.

Many attempts were therefore made, not only to substitute animals for men, for the work of propulsion, but to apply power in a manner more suitable than by the primitive³¹ method of levers: oars or sweeps. The paddlewheel was thought of at a very early date; a Roman army is said to have been transported into Sicily by boats propelled by wheels moved by oxen, and in many old military treatises³³ the substitution of wheels for oars is mentioned.131 In 1588 Ramelli, engineer-in-ordinary to the French king, published a book in which was sketched³⁴ an amphibious vehicle propelled by hand-worked paddlewheels: “une sorte de canot automobile³⁵ blindé et percé de meurtrières pour les arquesbusiers.” In 1619 Torelli, Governor of Malta, fitted a ship with paddles, and in it passed through the Straits of Messina against the tide. But Richelieu, to whom he offered his invention, was not impressed with its value.132 Before this, Blasco de Garoy, a Spanish captain, had exhibited to the Emperor Charles V, in 1543, an engine by which ships of the largest size could be propelled in a calm: an arrangement of hand-operated paddlewheels.

In Bourne’s Inventions and Devices, published in 1578, is the first mention of paddlewheels (so far as we know) in any English book. By the placing of certain wheels on the outside of the boat, he says, and “so turning the wheels by some provision,” the boat may be made to go. And then he proceeds to mention the inversion³⁶ of the paddlewheel, or the paddlewheel which is driven, as distinguished³⁷ from the paddlewheel which drives. “They make a watermill in a boat, for when that it rideth at an anker, the tide or stream will turn the wheels with great force, and these mills are used in France,” etc. It is possible, indeed, that this was the prior form, and that the earliest paddlewheel was a mill and not primarily a means of propelling the vessel.

Early in the seventeenth century the mechanical sciences began to develop rapidly and as the century advanced the flood of patents for the propulsion of ships increased. “To213 make boats, ships, and barges³⁸ to go against the wind and tide”; “the drawing and working of barges and other vessels without the use of horses”; “for making vessels to navigate⁴⁰ in a straight line with all winds though contrary”; these are some of the patents granted, the details of which are not known. At last the ingenious Marquis of Worcester, who in 1663 was granted a patent for his steam engine, also obtained a patent for an invention for propelling a vessel against wind and stream. It has sometimes been inferred that this invention was connected in some way with the steam engine, and the claim has been made that the Marquis was one of the first authors of steam propulsion. This is not so. Contained in the description of the ship-propelling invention are two statements which dispose completely of the theory that steam was the motive⁴¹ force; first, that the “force of the wind or stream causeth its (the engine’s) motion”; secondly⁴², that “the more rapid the stream, the faster it (the vessel) advances against it.” From this it appears that the Marquis intended to utilize⁴³ the watermill as described by Bourne. From a study of the description of the apparatus⁴⁴ it has been concluded that “a rope fastened at one end up the stream, and at the other to the axis⁴⁵ of waterwheels lying across the boat, and dipping into the water so as to be turned by the wheels, would fulfil the conditions proposed of advancing the boat faster, the more rapid the stream; and when at anchor such wheels might have been applied⁴⁶ to other purposes.”133 If this reconstruction⁴⁷ is correct, the scope of the propelling device was very limited.

In Bushnell’s Compleat Shipwright⁴⁸, published in 1678, a proposal was made for working oars by pivoting⁵⁰ them at the vessel’s side and connecting their inboard ends by longitudinal rods operated by cranks geared to a centre-line capstan. But the disadvantages of oars so used must have been apparent, and there is no evidence that this invention was ever put into practice. The obvious alternative was the paddlewheel, and though that device had been known and used in a primitive form long before the seventeenth century, it was continually being reinvented (especially in the ’nineties) and tried by inventors in various countries. Denis Papin turned his original mind to the solution of this problem. A paper on the subject written by him in Germany in 1690 is of interest. Discussing the use of oars from ships’ sides he notes that, “Common oars214 could not be conveniently used in this way, and it would be necessary to use for this purpose those of a rotary⁵² construction, such as I remember to have seen at London. They were affixed⁵³ to a machine made by direction of Prince Rupert, and were set in motion by horses, so as to produce a much greater velocity⁵⁴ than could be given by sixteen watermen to the Royal Barge³⁹.” Papin, who had suggested the atmospheric⁵⁵ steam engine, also suggested the possible application of steam to propulsion. But it was left to others to achieve what he had to propose. His talent, it has been said, lay rather in speculations⁵⁶ on ingenious combinations, than in the mechanical power of carrying them into execution on a great scale. In 1708 he laid before the Royal Society, accompanied by a letter of recommendation from Leibnitz, a definite proposal for a boat “to be moved with oars by heat ... by an engine after the manner that has been practised at Cassel.” What form this engine was to take, and how the power was to be transmitted to the oars, is still a matter of conjecture⁵⁷. Only this is known, that the proposal was considered in detail by the president, Sir Isaac Newton, and that on his advice no further action was taken.134

In France it has been widely claimed that Papin actually engined a boat and propelled it over the waters of the Weser by the force of steam. His biographer states that on the 24th September, 1707, Papin “embarquait sur le premier⁵⁸ bateau à vapeur toute sa fortune.”135 But the statement is not correct. The misconception, like that which assigned to the Marquis of Worcester the invention of a steam-propelled vessel, was doubtless due to the fact that the inventor was known to be engaged in the study of the steam engine and of ship-propelling mechanism⁵⁹. The two things, though distinct in themselves, were readily combined in the minds of his admirers. It is generally agreed to-day, we think, even by his own countrymen, that Papin, though he may claim the honour of having first suggested the application of steam to ship propulsion, never himself achieved a practical success.

In the meantime Savery in England had produced his successful engine. In his case, too, the claim has been made that he first proposed steam propulsion for ships. But in his Miner’s Friend this able mechanician showed that he recognized215 the limited application of his steam engine. “I believe,” he says, “it may be made very useful to ships, but I dare not meddle⁶⁰ with that matter; and leave it to the judgment⁶¹ of those who are the best judges of maritime⁶² affairs.” But in propulsion by hand-operated paddlewheels Savery was an enthusiastic believer. In 1698 he had published, in a book bearing the title, “Navigation Improv’d: Or the Art of Rowing Ships of all Rates, in Calms, with a more easy, swift, and steady Motion than Oars can,” a description of a mechanism consisting of paddlewheels formed of oars fitted radially to drumheads which were mounted on the two ends of an iron bar placed horizontally across the ship. This bar was geared by mortice wheels with another bar mounted vertically⁶³ as the axis of a capstan; rotation⁶⁵ of the capstan was thus transmitted to the paddlewheels. Savery fitted this mechanism to a wherry and carried out successful trials on the Thames before thousands of people. But the Navy Board would not consider it. They had incurred⁶⁶ a loss, it appeared, on a horse tow-vessel which had been in use at Chatham a few years previously⁶⁷: a vessel which towed the greatest ships with the help of four, six, or eight horses, and which, incidentally, may have influenced Savery in adopting the term “horse power” as the unit of work for his steam engine. The sanguine⁶⁸ inventor made great efforts to interest the authorities, but without avail; the Surveyor rejected the proposal. So in an angry mood Savery published his book, with a description of his mechanism and an account of his efforts to interest the authorities, to show how one man’s humour had obstructed⁶⁹ his engine. “You see, Reader, what to trust to,” he concluded, “though you have found out an improvement as great to shipping⁷⁰ as turning to windward, or the compass; unless you can sit round the green table in Crutched⁷¹ Friars, your invention is damned of course.”

The first detailed⁷² scheme for applying steam-power to ship propulsion was contained in the patent of Jonathan Hulls⁷⁴, in 1736. Though great credit is generally given to this inventor (who has even been dubbed⁷⁶ the father of steam navigation), it does not appear that in reality he contributed much to the advancement⁷⁷ of the problem; which was, indeed, still waiting on the development of the steam engine. Hulls’ notion, explained in a pamphlet which he published in 1737, was to connect the piston⁷⁸ of a Newcomen engine by a rope gearing216 with some wheels mounted in the waist of the vessel, which wheels oscillated as the piston moved up and down. These wheels were in turn connected by rope gearing with a large fan-wheel mounted in a frame rigged out over the vessel’s stern, the fans in their lowest position dipping into the water. The oscillating motion of the inboard wheels was converted into a continuous ahead motion of the fan-wheel by means of a ratchet. With this machinery⁷⁹ he designed to tow ships in harbours and rivers. It must, however, be remarked that the invention was never more than a paper project; and that if Hulls had tried to translate his ideas into three dimensions he would have encountered, in all probability, insuperable practical difficulties. One very original suggestion of his certainly deserves notice; as a special case he proposed that when the tow-boat was used in shallow rivers two cranks, fitted to the axis of his driving wheels, should operate two long poles of sufficient length to reach the bottom of the river; these trailing poles, moving alternately forward, would propel the vessel. Here is an early application of the crank. But in this case it will be noted⁸⁰ that the crank is driven, and that it converts a rotary into a reciprocating⁸¹ motion; in short, it is an inversion of the driving crank which, as applied to the steam engine, was not invented till some years later.

As before remarked, the whole problem of steam propulsion waited upon the development of the steam engine. In the meantime the application of convenient forms of man power received considerable study, especially in France. In Bouguer’s Traité du Navire the problem was investigated of propulsion by blades or panels, hinged, and folding when not in use against the vessel’s sides; and in 1753 the prize offered by the Academy of Sciences for an essay on the subject was won by Daniel Bernouilli, for a plan on those lines. Euler proposed paddlewheels on a transverse shaft⁸² geared like Savery’s, by mortice wheels to a multiple capstan. Variations of this method were proposed by other writers and inventors, and some of the best intellects in France attacked the problem. But nothing definite resulted. The most valuable result of the discussion was the conclusion drawn⁸³ by M. Gautier, a professor of mathematics at Nancy, that the strength of the crew was not sufficient to give any great velocity to a ship. He proposed, therefore, as the only means of attaining⁸⁴ that object, the217 employment of a steam engine, and pointed⁸⁵ out several ways in which it might be applied to produce a rotary motion.136

In the course of time the problem marched forward to a solution. The first great improvement in the steam engine which rendered it adaptable⁸⁶ to marine⁸⁷ use was the invention by Watt⁸⁸ of the “double impulse”; the second, Pickard’s invention of the crank and connecting-rod. By virtue⁸⁹ of these two developments the steam engine was made capable of imparting to a shaft a continuous rotary motion without the medium of noisy, brittle⁹⁰ or inefficient⁹¹ gearing. As soon as engines having this power were placed on the public market attempts were made to mount them in boats and larger vessels; steam navigation was discerned as a possibility.

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Of the many efforts which were made at the end of the eighteenth century to apply steam power to the propulsion of ships a striking feature is their complete independence from each other and from the results of prior experience and research. Little information is available as to the results of various experiments which were known to be carried on in France at this time, and, with all respect, it is improbable that they contributed in any way to the subsequent evolution of the steam vessel. The Abbé Darnal in 1781, M. de Jouffroi in 1782, and M. Desblancs in 1802 and 1803, proposed or constructed steamboats. M. de Jouffroi is said to have made several successful attempts on the Saone at Lyons; but the intervention⁹² of the Revolution put an end to his undertakings⁹³.

In Britain a successful attempt to apply the steam engine to the paddlewheel was made in 1788. In that year three men, combining initiative, financial resource, and a large measure of engineering ingenuity⁹⁴, proved the possibility of steam propulsion in an experiment singularly complete and of singularly little effect on subsequent progress. In the summer of ’87 a wealthy and inventive banker, Mr. Patrick Miller⁹⁵ of Dalswinton, Edinburgh, had been making experiments in the Firth of Forth⁹⁶ with a double vessel of his own invention, sixty feet long, which, when wind failed for sailing, was set in motion by two paddlewheels. These paddlewheels were fitted between the two hulls of the vessel and were worked by men, by means218 of a geared capstan. Miller believed that a boat furnished with paddlewheels and worked manually would be of great advantage for working in shallow rivers and canals. But the result of a sailing race between his boat and a custom-house wherry of Leith, in which his own sails were supplemented by the labours of four men at the wheels, convinced him that manpower was insufficient⁹⁷. His sons’ tutor, a Mr. Taylor, suggested the application of a steam engine. And being acquainted with an engineer named Symington, Taylor prevailed on his patron to engage him to mount a one-horse-power engine in a double pleasure boat, upon the lake at Dalswinton. The experiment was a complete success. “The vessel moved delightfully⁹⁸, and notwithstanding the smallness of the cylinder¹⁰⁰ (4 inches diameter), at the rate of 5 miles an hour. After amusing ourselves a few days the engine was removed and carried into the house, where it remained as a piece of ornamental¹⁰¹ furniture for a number of years.”137 Determined¹⁰² to pursue the experiment, Miller ordered a replica¹⁰³ of the original engine on a larger scale, and this engine, with a cylinder of 18 inches diameter, was erected¹⁰⁴ at Carron and fitted to a larger boat. This also was successful. But no further trials were made after ’89; for Patrick Miller, who had spent a large sum in order to establish the feasibility of the invention, decided¹⁰⁵ to close his investigations¹⁰⁶, and to turn to other pursuits.

No further attempt was made in Great Britain until 1801, when Lord Dundas engaged Symington to make a series of experiments on the substitution of steam power for horse towage of barges on the Forth and Clyde canal: experiments which resulted in the Charlotte Dundas. In this celebrated¹⁰⁷ vessel a double-acting¹⁰⁸ Watt engine, with its 22-inch diameter cylinder mounted horizontally on the deck, actuated, through a simple connecting-rod and a crank with a 4-foot throw, a paddlewheel which was carried in a centre-line recess¹⁰⁹ at the stern. In March, ’03, Symington in the Charlotte Dundas towed two 70-ton vessels nineteen miles against a strong head wind in six hours. Success seemed assured to him. His reputation was already high, and now an invitation came from the Duke of Bridgewater for eight similar tow-boats to ply²⁹ on his canal. But the inventor’s hopes were disappointed. The Duke died suddenly, and the governing body of the Forth219 and Clyde canal vetoed the further use of steam vessels for fear of the damage the waves might cause the banks. Other bodies took the same view, and thus came to an end an important passage in the history of steam navigation. It is remarkable¹¹⁰, considering the efforts which had been made by inventors from the sixteenth century onwards to improve on oar-propulsion for military purposes, that Miller, Symington, and their friends do not seem to have envisaged¹¹¹ any use for steamboats other than as tugs¹¹³ on canals. It is remarkable that in the presence of this initial success neither the government nor the public showed any realization¹¹⁴ of the possibilities which it unfolded; that no attempt was made by commercial enterprise—even if, in the realm of naval strategy, such an innovation was regarded as impolitic or impracticable138—to develop its advantages and to secure an undisputed lead in the new application of steam power.

THE “CHARLOTTE DUNDAS”

(From Fincham.)

It was in America that the most persistent¹¹⁵ and continuous development took place, quite independently of efforts elsewhere and almost contemporaneously with those above described. America, whose geographical¹¹⁶ conditions made water transport relatively¹¹⁷ far more important than it was in Great Britain, lent a ready ear to the schemes of inventors. In220 1784 James Rumsey, and shortly afterwards John Fitch, had already laid plans before General Washington for the propulsion of boats by steam.

John Fitch, whose original idea was a steamboat propelled by means of an endless chain of flat boards, afterwards experimented with an arrangement, “borrowed no doubt from the action of Indians in a canoe,” of paddles held vertically in frames mounted along the sides of the boat and operated by cranks. In 1786 a boat thus equipped made a successful trial on the Delaware, and in the following year a larger boat, fitted with a horizontal double-acting engine with a 12-inch cylinder and a 3-foot stroke, giving motion to six paddles on each side, was publicly tried on the same river. The speed attained was very small. At last in 1790, still protected by a patent which granted him a temporary monopoly in steamboat building, Fitch succeeded in building a boat which was an undisputed mechanical success. Discarding the paddle-frame and adopting a beam engine to drive paddle-boards at the stern, he produced a steamboat which, after being tested and credited with eight knots’ speed on a measured mile in front of Water Street, Philadelphia, in the presence of the governor and council of Pennsylvania, ran two or three thousand miles as a passenger boat on the Delaware before being dismantled¹¹⁸. It was a considerable achievement. But the excessive weight and space absorbed by the machinery prevented the boat from being a financial success; and, after a journey to France, then distracted by the Revolution, Fitch returned home to America and ended his days a disappointed and a broken man. Nevertheless, the work he did was of service to others. He proved that the ponderous¹¹⁹ nature of the machinery was the greatest obstacle to the propulsion of small craft by steam, and from his failure deduced the conclusion, on which later inventors were able to build, that the solution of the problem lay in the scale: that, “it would be much easier to carry a first-rate man-of-war by steam at an equal rate than a small boat.”139

James Rumsey, a Virginian, carried out in 1775 the first practical trials of water-jet propulsion, a small boat of his plying⁷³ the Potomac at a small speed by means of a steam pump which sucked in water at the bow and threw it out at the stern. But as he felt himself obstructed in further experiments by the221 patent rights which had been given his rival Fitch he came to England; where, financed by a wealthy compatriot and aided by James Watt himself, he produced in ’93 a boat which on the Thames attained a speed of over four knots. Unfortunately Rumsey died in the middle of his experiments.

An individual of extraordinary qualities had now turned his attention to the problem of steam propulsion. In that same year a young American artist, Robert Fulton, who had come to England to work under the guidance of his countryman Benjamin West, wrote to Lord Stanhope informing him of a plan which he had formed for moving ships by steam. Lord Stanhope, well known as a scientific inventor, had recently been experimenting with a vessel fitted with a 12-horse-power engine of Boulton and Watt’s working a propeller¹²⁰ which operated like the foot of an aquatic¹²¹ bird. A correspondence ensued. Fulton, whose self-confidence equalled his originality¹²², illustrated¹²³ by drawings and diagrams his ideas on the subject. At first, he said, he thought of applying the force of an engine to an oar or paddle which, hinged on the counter at the stern, by a reciprocating motion would urge the vessel ahead. But on experimenting with a clockwork model he found that, though the boat sprang forward, the return stroke of the paddle interfered¹²⁴ with the continuity of the motion. “I then endeavoured,” he wrote, “to give it a circular motion, which I effected by applying two paddles on an axis. Then the boat moved by jerks; there was too great a space between the strokes. I then applied three paddles, forming an equilateral triangle to which I gave a circular motion.” These paddles he proposed to place in cast-iron wheels one on each side of the boat and mounted on the same shaft at some height over the waterline, so that each wheel would “answer as a fly and brace¹²⁵ to the perpendicular¹²⁶ oars.” And he stated that he found, from his experiments with models, that three or six oars gave better results than any other number. From which it is clear that the paddlewheel was evolved by Fulton from the simple paddle independently of suggestion received from previous inventors.

Some time was to elapse before the results of his experiments were utilized¹²⁷. Attracted by the boom in canal construction then in vogue¹²⁸ Fulton devoted¹²⁹ his mind to that subject; though in this connection the idea of steam-propelled boats still occupied him, as is shown by a letter he wrote in ’94 to Messrs. Boulton and Watt, asking for an estimate of costs222 and dimensions of “an engine with a rotative movement of the purchase of 3 or 4 horses which is designed to be placed in a boat.” From England he went to Paris, to try his fortune at half a dozen projects. In ’98 he was experimenting on the Seine with a screw propeller—“a fly of four parts similar to that of a smoke-jack,” which gave promising¹³⁰ results. This screw propeller, however, was as yet unrecognized as the propulsive¹³¹ medium of the future. It had already been patented in England by Bramah in 1785—“a wheel with inclined fans, or wings, similar to the fly of a smoke-jack or the vertical⁶⁴ sails of a windmill”; and, hand-operated, it had actually been used in America in 1776 by Bushnell in connection with his submarine. But in 1802 Fulton had decided against the screw, and in favour of the paddlewheel.

It was in this year that an introduction to an influential¹³² compatriot, himself an experimenter in steam propulsion, gave Fulton the opportunity to display his talents to their mutual¹³³ advantage. Chancellor¹³⁴ Livingston, U.S. Minister to France, was aware of the enormous advantages which would accrue¹³⁵ to America (and to the happy inventor) if steam propulsion could be achieved economically. With Fulton’s aid he decided on building an experimental steam vessel in France, with a view to transferring to America for commercial enterprise the perfected results of their labour. A partnership¹³⁶ was formed, the work proceeded; but the experimental steamboat, whose scantlings were unequal to supporting the weight of the 8-horsepower machinery placed on board, sank at her moorings in a storm. A second boat, stronger and bigger, attained complete success. Fulton promptly¹³⁷ wrote to Messrs. Boulton and Watt asking them to export to America a 24-horse-power engine complete with all accessories, in accordance with his sketches¹³⁸; and with a brass¹³⁹ air-pump suitable for working in salt water. Then, going himself to England, he visited Messrs. Boulton and Watt and gleaned¹⁴⁰ what information he could as to the properties of their machinery; studied the newly published results of Colonel Beaufoy’s experiments on ship form and fluid resistance; and journeyed to Scotland to visit Symington and see the famous Charlotte Dundas.

Armed with this knowledge, with all the experience of Rumsey and Fitch, and with the data from his own trials, Fulton brought to a successful solution the problem of steam propulsion on a commercial scale. It has been remarked223 that there was no element in the Clermont or her successors so original in conception that it would entitle Fulton to be regarded as the inventor of steam navigation. Nor did he himself claim to be such. He was successful in fitting together the elements, the inventions of others. Science is measurement, and Fulton applied his data and measured with great insight, adapting his elements in the right manner and proportion to form an efficient whole. “He was the first to treat the elementary factors in steamship¹⁴¹ design—dimensions, form, horse-power, speed, etc.—in a scientific spirit; to him belongs the credit of having coupled the boat and engine as a working unit.” From Fitch he had learned the economy of size, and the advantages of enlarging the scale of operations; from Beaufoy, the importance of a fair underwater form, with a sharp bow and stern. From Symington, who generously took him for a trip in the Charlotte Dundas, he could not fail to have gleaned much practical advice and information; it is remarkable, in this connection, that, after a sight of Symington’s horizontal cylinder with its simple connecting-rod drive to the stern wheel, he should have adhered to the vertical cylinder and the bell-crank or beam for the transmission of the force: an initial divergence¹⁴² which was perpetuated¹⁴³, and which became the hall-mark distinguishing American from English practice for some years to come. Most of his knowledge he gained by his activities in England, and many writers have contested a claim—which so far as is known was never made by him—to the invention of the steamship. His achievements were well defined and legitimately¹⁴⁴ executed, and the remarkable insight and initiative which he displayed in adapting the labours of others to serve his own utilitarian¹⁴⁵ ends cannot, surely, deserve the opprobrium¹⁴⁶ cast on them by some of the nineteenth-century writers. Prometheus, it is said, stole fire from heaven. Fulton bought his in the open market; obtaining his engine in Soho and his boiler¹⁴⁷ in Smithfield he transported them across the Atlantic, and in 1807 produced the Clermont.

The Clermont, a flat-bottomed wall-sided craft 166 feet in length and only 18 feet in beam, steamed at a speed of five knots from New York to Albany, in August, 1807; to the surprise of thousands of spectators who knew her as “Fulton’s folly,” and whose shouts of derision gave place to silence, and then to a chorus of applause and congratulation. Many of the224 inhabitants of the banks of the Hudson had never heard even of an engine, much less of a steamboat. “A monster moving on the waters, defying the winds and tide, and breathing flames and smoke! The first steamboat used dry pine wood for fuel, which sends forth a column of ignited vapour many feet above the flue, and, whenever the fire is stirred, a galaxy¹⁴⁸ of sparks fly off which, in the night, have a very brilliant and beautiful appearance.”140 The Clermont was followed by others, each an improvement on the last; until in 1816, so rapid was the process of evolution, the Chancellor Livingston was built, ship-shaped, with figure-head and fine bows, faired sides and tapering¹⁴⁹ stern, with engines of 75-horse-power and with promenade¹⁵⁰ decks and accommodation for 120 passengers. Certain characteristics now showed themselves in all American construction. The engines were mounted with cylinders¹⁵¹ vertical, their rods actuating large overhead beams which transmitted the force of the steam to the paddlewheels. The boats were made very broad to give the necessary stability, the machinery being carried high; and to reduce their underwater resistance as much as possible their bodies were made full near the water-line and lean below. For the same reason, and since the principal weights were concentrated amidships, fine forward and after bodies were given them; a rising floor, and a deep draught¹⁵² if necessary. The position of the paddlewheels was limited by that of the engine. Experience showed that where two paddles on each side were used their relative position had to be adjusted nicely, otherwise the rear paddles, acting on accelerated water, might actually be a disadvantage. Much difficulty was caused with accidents to paddles; on the Mississippi the wheels were generally mounted astern, where they were protected from floating logs of timber. In some cases double hulls were built, with the paddlewheels between them; but owing to the rush of water on which they acted these wheels were not very efficient.141

THE COMET OF 1812

From an oil painting in the South Kensington Museum

Fulton had so far built steam vessels only for commercial traffic. He now came near to revolutionizing naval warfare with them. In 1813, in the middle of the war with this country, he presented to the President his plan for a steam-propelled armoured warship for coast defence, a design of an invulnerable225 vessel of thirty guns, twin-hulled, with a 120-horse-power engine in one hull⁷⁵, a boiler in the other, and a single paddlewheel in a space between the two; double-ended, flat-bottomed, and protected by a belt of solid timber 58 inches thick. Her armament was to consist, in addition to thirty 32-pounders, of submarine guns or columbiads, carried at each end and firing 100-pound projectiles¹⁵³ below the water-line. Named the Demologos, this monstrous¹⁵⁴ vessel was nearly completed when the war came to an end. It was too late for use. The treaty of Ghent being signed, interest in armaments immediately evaporated. Nevertheless, in the following year a trial of the Demologos was carried out, which showed that a speed of five and a half knots could be attained with her. The Demologos, now renamed the Fulton, served no useful purpose. She was laid up in Brooklyn Navy Yard, and many years elapsed before steam war vessels were built again in America.

§

In the meantime progress had been made on this side of the Atlantic. Stimulated¹⁵⁶ by Fulton’s commercial successes, Thomas Bell of Helensburgh built in 1812 a vessel of thirty tons’ burden named the Comet, successfully propelled by a 3-horse-power engine which worked a paddlewheel on each beam. This “handsome vessel” was intended to ply between Glasgow and Greenock, to sail by the power of wind, air, and steam; and so it did, with fair financial success, with a square sail triced to the top of a tall smoke-stack: the first passenger steamer to ply in European waters. Shortly afterwards steam vessels were built which pushed out to the open sea. In 1815 the Argyle, built on the Clyde and renamed Thames on being purchased by a London company, made a voyage from Greenock to London which was the subject of much comment. On making the Cornish coast after a stormy run south, boats were seen by those on board making towards her with all possible speed in the belief that she was on fire! All the rocks commanding St. Ives were covered with spectators as she entered the harbour, and the aspect of the vessel, we are told, “appeared to occasion as much surprise amongst the inhabitants, as the ships of Captain Cook must have produced on his first appearance among the islands of the South Seas.” Next226 day the Thames, her 9-foot paddlewheels driven by a 16-horse-power engine, reached Plymouth, where the crews of all the vessels in the Sound filled the rigging, and the harbour-master was “struck with astonishment¹⁵⁷.” From Plymouth she steamed to Portsmouth, making the passage in twenty-three hours. So great was the swarm¹⁵⁸ of vessels that crowded round her, that the port admiral was asked to send a guard to preserve order. She steamed into harbour, with wind and tide, at from twelve to fourteen knots. A court-martial was sitting in the Gladiator frigate¹⁵⁹, but the whole court except the president adjourned¹⁶⁰ to inspect the strange visitor. Next day the port admiral sent off a guard and band; and soon afterwards he followed, accompanied by three admirals, eighteen post captains, and a large number of ladies.142

The success of the Thames led to the immediate¹⁵⁵ building of other and larger steamers. In ’17 the son of James Watt purchased a 94-foot boat, the Caledonia, fitted her with 28-horse-power machinery driving 10-foot paddlewheels, and for a pleasure trip proceeded in her up the Rhine as far as Coblentz. From this time onwards steam navigation for commercial purposes progressed rapidly. In 1818 a steamboat made regular voyages at sea; the Rob Roy, 90 tons, built by Denny of Dumbarton, with engines of 30 horse-power made by Napier, plied regularly between Holyhead and Dublin. In the same year the Savannah, a ship of 350 tons’ burden built and fitted with auxiliary¹⁶¹ steam machinery at New York, crossed the Atlantic, partly under steam; her paddlewheels with their cast-iron frame and axletree successfully withstanding heavy weather. In ’21 the postmaster-general introduced a steam service for the mails at Dover and Holyhead; and in the following year there were steamboats running between London and Leith, and other seaports¹⁶². The experience of the Holyhead packets was of special value, as it proved that steam vessels could go to sea in weather which would keep sailing vessels in harbour. Soon after this the question was raised of employing steam power to shorten the passage between England and the East, as well as of the navigation by steam of the great Indian rivers. Steam superseded¹⁶³ sails in the government mail service between Falmouth, Malta and Corfu; everywhere commercial enterprise was planning new lines of steamships¹⁶⁴ and new possibilities of ocean travel. In ’25 a227 barque belonging to Mr. Pelham, afterwards Earl of Yarborough, was fitted with steam machinery as an auxiliary and made the voyage to India. The plash of the paddlewheel was then heard for the first time in Oriental waters.

By this time the great question of steam as applied to naval ends had arrived to agitate¹⁶⁵ the Admiralty.

In ’22 M. Paixhans discharged his revolutionary treatise³² at the French nation, advocating, with a wealth of argument, a navy of steam-propelled warships¹⁶⁶ armed with a few shell guns. Six years later a warning echo reverberated¹⁶⁷ through Whitehall. Captain Sir John Ross published a volume on “Steam Navigation, with a System of the Naval Tactics peculiar¹⁶⁸ to it,” in which, though his name was not mentioned, the arguments of M. Paixhans were set forth from an opposite point of view. The two books, starting with the same arguments, arrived at diametrically opposite conclusions. While Paixhans claimed that steam power offered important advantages to France, the English writer reached the gratifying conclusion that the change which steam would effect in naval affairs might be rendered favourable¹⁶⁹ to this country. For coast defence alone steam vessels would be invaluable¹⁷⁰. The colonies would be safer from piracy¹⁷¹. Passages, at present difficult or dangerous, would be made with speed and safety. Incidentally, an entirely¹⁷² new system of tactics would be evolved by the coming of steam; each ship-of-the-line would be escorted by a steam vessel, to tow her into position, and concentration of force would be obtained by such means as, harnessing two steamers to one sailing ship, so as to tow one half of the fleet to a position of vantage over the enemy. After the main action the steamers would themselves attack each other; and so on. Both French and English writers agreed that there would be a reversion to the ancient warfare of the galleys; the steamer, whose paddlewheels lent themselves readily to a pivot⁴⁹ gun armament and to great powers of man?uvring, would always attack like a bull, facing the enemy, its bows presenting one or more large and well-protected cannon. Sir John Ross regarded the steamer, however, essentially¹⁷³ as an auxiliary. M. Paixhans took a more sanguine view. “At this moment,” he wrote in May, ’22, “the English admiralty are building two steam vessels, each of thirty horsepower, one at Portsmouth and one at Plymouth, for tugging¹⁷⁴ sailing ships held up by contrary winds. They commence by228 being the servitors of the ships-of-the-line; but it is their destiny to become their masters.”143

But the views of Sir John Ross did not find favour at the Admiralty. In the presence of the revolution the authorities continued to steer¹⁷⁵ a policy of passive resistance to all changes and methods which might have the effect of depreciating¹⁷⁶ existing naval material; and Lord Melville himself penned, as a reply to the Colonial Office to a request for a steam mail service between two Mediterranean ports, the principle which guided the Board. They felt it their bounden duty (he wrote in 1828) to discourage, to the utmost of their ability, the employment of steam vessels, as they considered that the introduction of steam was calculated to strike a fatal blow at the naval supremacy¹⁷⁷ of the Empire.144145

So far, then, new methods of propulsion had not been greeted with enthusiasm. Yet to the First Lord himself was due the utilization¹⁷⁸ of steam for minor¹⁷⁹ purposes in the navy. In spite of the non-success of Lord Stanhope’s experimental “ambi-navigator” ship in 1795, Lord Melville in 1815 caused the three-masted schooner¹⁸⁰ Congo, designed for a surveying expedition to the river of that name, to be fitted with paddlewheels and machinery by Boulton and Watt, expressly to try it in a ship-of-war. This machinery was so large and ponderous that, not only did it usurp¹⁸¹ one-third of the space aboard the ship, but brought her down so deep as only to give four knots through the water. It was all removed again before she sailed, and sent to Chatham for use in the dockyard. In the following year we find Mr. Brunel in correspondence with his lordship on the question of steam navigation. Brunel wrote quoting evidence to the effect that paddlewheels could be made229 of sufficient strength and stiffness to withstand the violence of seas and gales¹⁸²; to which Lord Melville replied that the Board deemed it unnecessary to enter, at that time, into the question of steam navigation generally, but desired his views on the application of steam to the towing of ships-of-war out of harbour against contrary winds and tides: which would be a matter of great advantage to his Majesty’s service. Brunel answered recommending that the steamer Regent, plying between Margate and London, be chartered during the winter and employed on this work, as a particular experiment.

“From this period may be dated the introduction of steam navigation into the English navy. Lord Melville was now so fully⁹⁹ convinced of the great utility which the naval service would derive¹⁸³ from it, that he ordered a small vessel to be built at Deptford, by Mr. Oliver Lang, to be called the Comet, of the burthen of 238 tons, and to have engines of 80 horse-power. She was built accordingly and ready for sea in 1822.”146 As a matter of fact, the first steamer actually brought into H.M. service was the Monkey, built at Rotherhithe in 1821; and she was followed by the more powerful Sprightly¹⁸⁴, built at Blackwall by Messrs. Wigram and Green in ’23. Gradually the use of these paddlewheel tugs extended, their tonnage and horse-power increased, and the Surveyor of the Navy and his master shipwrights¹⁸⁵ began to divert their talents to a consideration of the small steamers.

For the reason stated by Lord Melville, steamers were at this time tolerated only for towing and other subsidiary duties; authority poured cold water on the idea of utilizing¹⁸⁶ them as ships-of-war; and if steam could have been dispensed¹⁸⁷ with altogether, everyone would have been the better pleased.

Even at this period the idea of using manual labour, applied in an effective manner, for towing and bringing into position sailing warships had not been altogether abandoned. In 1802 the transport Doncaster had been propelled at a slow speed in Malta harbour by the invention of a Mr. Shorter: a screw propeller rigged over the stern. In 1820 experiments were made at Portsmouth with paddlewheels manually worked, and in ’29 Captain C. Napier took his ship Galatea out of Portsmouth Harbour by use of paddlewheels geared to winches230 which were worked by the crew. One hundred and thirty men were able to give her a speed of 2? knots, while the full crew of a hundred and ninety produced a speed of three. After this doubtful success another trial was held—a race between the Galatea, propelled by paddles, and the Briton, towed by boats—which Galatea won. Captain Napier’s paddlewheels afterwards did good work for his ship in other quarters of the world.147 Nothing resulted, however, from his initiative in this connection; only was emphasized the enormous superiority of steam-propelled vessels as tugs, in which capacity they had already made their appearance, and from which they were destined¹⁸⁸ to evolve, in the next decade, into fighting vessels of considerable force.

By 1830 steam navigation had made significant strides along the lines of commercial development. In that year a service of steam mail boats started to run at regular intervals¹⁸⁹ between Falmouth and Corfu, covering the distance in about one-fourth of the time which had been taken by the sailing packets; a Dutch government steamer, the Cura?oa, built in England, had since ’27 been running between Holland and the East Indies; and already the Indian Government had built an armed steamer, designed as the forerunner¹⁹⁰ of others which were to connect Bombay with Suez and thus to place India in more direct communication with England.

The navy was still represented only by paddle-tugs. With a change of administration, however, came a change in Admiralty policy. The new Board took a distinctly progressive view. It was agreed that, if foreign powers initiated¹⁹¹ the building of steam war-vessels, this country must build as well, and not only as well but better: a policy tersely¹⁹² summed up by Admiral Sir T. M. Hardy¹⁹³ in his saying, “Happen what will, England must take the lead.” Certain objections to steam vessels as naval units which had hitherto held a vogue were now seen to be ill-founded or baseless. In particular it was discovered, not without surprise to many, that steamers could be man?uvred without difficulty. A paddlewheel steamer, the Medea, gained her commander considerable credit from the skill with which she was navigated¹⁹⁴ from the Thames into the basin at Woolwich dockyard, which proved that steamers could be steered¹⁹⁵ and man?uvred better than231 sailing ships. In ’33 the construction of steamers was placed in the hands of the Surveyor.148

But small progress was made. One reason alleged¹⁹⁶ was that the shape of hull which the Surveyor had made peculiarly his own was ill-adapted for steam machinery. “Nothing more unpropitious,” observed a later writer, “for Sir William Symond’s mode of construction than the introduction of steam can be conceived. His sharp bottoms were the very worst possible for the reception of engines; his broad beam and short length the most unfavourable qualities that could be devised for steam propulsion. As much as he could, he adhered to his principles.... Rather than yield to the demands of the new power, he sacrificed the armaments of his vessels, kept down the size of their engines, and recklessly exposed the machinery to shot should they go into action.”149 There doubtless was something in this criticism. And yet, as we have seen, experience in America led to a form of hull for paddle steamers in many respects approaching that condemned¹⁹⁷ as being favoured by the Surveyor!

Another and more valid¹⁹⁸ reason for the slow progress made lay in the inherent unsuitability of the paddlewheel steamer as a substitute for the large sailing warship. Not only did the paddlewheels offer a large and vulnerable surface to destruction by enemy shot, but the wheels and their machinery could not be embodied¹⁹⁹ in a ship design without interference with its sails and sailing qualities and, still more, without serious sacrifice of broadside armament. The machinery monopolized²⁰⁰ a large section of the midship space, the huge wheels covered the sides and interfered with the training of those guns for which room remained. The problem of arming steam-vessels was novel and difficult of solution. The guns must be few and therefore powerful. Hence it appeared that paddlewheel steamers, notwithstanding the advantages they possessed²⁰¹ of speed and certainty of motion, could only sustain a small concentrated armament, consisting of the heaviest and most232 powerful ordnance²⁰²: guns of large calibre, which possessed large power of offence at ranges where the broadside cannon would be deprived of much of their efficiency. Hence in ’31 a 10-inch shell gun of 84 hundredweight was expressly designed and cast for this purpose; and all the classes of steamers in early use in the navy were armed with it until, in ’41, it was displaced by the 68-pounder pivot gun, which then became the principal pivot gun of the service. Thus the development of paddlewheel machinery reacted on the development of artillery. The steamer was a stimulus²⁰³ to the development of large ordnance worked on the pivot system. And this form of armament in turn influenced the form of the ship. The main weights—those of the propelling machinery—were already concentrated in the waist of the vessel, and it was now possible so to place the few pivot guns that the ends of the vessel were left very lightly loaded. Thus it was possible to give unprecedentedly²⁰⁴ fine lines to the new steamers, a sharp and lengthened²⁰⁵ bow and a well-tapered run: an improved form of body by the use of which high speeds were obtained. In the case of commercial steamships the advantages of fine lines had already been recognized, and their designers had been free to give them a form which would allow of a high speed being attained; but in the case of war vessels designed to carry a broadside armament the limitations imposed by the heavily weighted ends had hitherto prevented other than bluff²⁰⁶ bows and sterns being given them. But now the subject of ship form came under general consideration, and the new conditions led to a more serious study of the laws governing the motion of bodies through water.

Year after year the size of steamers grew.150 And as with size the cost of construction and maintenance increased, the question pressed itself more and more clearly—what was the naval utility of such expensive and lightly armed vessels? Numerous attempts were made to produce a form of paddlewheel steamer which would carry a broadside armament comparable with that which a sailing vessel of the same burthen233 would bear. In 1843 the Penelope, 46 guns, was cut in halves at Chatham and lengthened by the addition of about 65 feet, in which space engines of 650 horse-power were installed. But the extra displacement²⁰⁷ failed to compensate²⁰⁸ for the weight of the machinery; the altered vessel drew more water than had been anticipated and, though various alterations²⁰⁹ were made to minimize the effects of this, the experiment was not a success and was not repeated. In ’45 a steam frigate called the Odin was built by order of the Board. “The results aimed at in constructing this ship were—capability of carrying broadside armament; diminished rolling, in comparison with any war steamers then built; and less draught of water in relation to the size. These objects were accomplished²¹⁰; but as the position of the machinery and boilers²¹¹ is partially²¹² above the water-line, and the propellers²¹³ are exposed to danger in broadside fighting, the ship is necessarily imperfect in these two conditions, as well as in the position of the sails; for in this case the proper place of the mainmast was occupied by the boilers, and consequently the centre of effort of the wind on the sails is in a wrong place.”151 In the same year the Sidon was laid down, the design being on the lines of the Odin but modified in accordance with the ideas of Sir Charles Napier: with greater depth of hold and with machinery below the water-line. Iron tanks were placed in the hold for carrying the coals; by filling these with water when empty the steamer was kept at a more or less constant draught, a matter of considerable importance to the efficient working of the paddlewheels. In other respects, however, the Sidon was unsatisfactory. She was so crank that the addition of ballast and a modification²¹⁴ of her armament were necessary. Her engines were cramped²¹⁵, her boilers of insufficient power and of unsuitable design, and her coal capacity too small to give her a useful radius²¹⁶ of action. For the attainment²¹⁷ of all the properties specified²¹⁸ it was subsequently calculated and shown that a much larger displacement was necessary. Just as Fitch had discovered and Fulton had discerned, increase in scale reduced many of the difficulties encountered in designing heavily weighted steam vessels. Hence the success of the Terrible. In the case of the Terrible, a large paddlewheel frigate of 1,850 tons and 800 horse-power built in 1845, it was clear that an increase of size had given a partial solution to the problem of234 designing a war-vessel with heavy and spacious²¹⁹ propelling machinery, with adequate armament, and with full sail-power and all the properties of a sailing ship.

Still the steam war-vessel was not satisfactory. Her machinery usurped²²⁰ the weight and space required for armament, her cumbrous paddlewheels were far too exposed to damage by shot or shell. And how to surmount²²¹ these difficulties and reconcile the conflicting requirements of artillery and motive power, was a problem which cost the country years of unsuccessful experiments and millions of money. “It was,” said Dahlgren, “the riddle²²² of the day.”

§

The problem was solved by the adoption²²³ of the screw propeller.

Since Archimedes’ day the screw had been known in the form of a pump, and in two familiar objects—the smoke-jack and the windmill—the principle of the driven screw had been for centuries widely employed. In connection with ship propulsion the screw appears to have been tried at an early date, like the Marquis of Worcester’s water-wheel, in the form of a mill. Among the machines and inventions approved by the Royal Academy of Sciences of Paris between the years 1727 and 1731 is one described as a screw, suspended in a framework between two boats, which when acted upon by the current was intended to warp²²⁴ the vessels upstream, the motion of the screw being transmitted to a winch barrel on which a tow-rope was wound. But so far as is known no attempt had been made at this date to use the screw directly as a propeller. In 1768 its use in this form was suggested in a work entitled Théorie de la Vis d’Archimede.152 And shortly after, as we have already seen, Bramah in England and Bushnell in America235 had patented, and the latter had actually put into use, the screw as a means of propelling vessels through water. We have seen, too, that Fulton successfully adapted the screw propeller, on a small scale, in one of his experimental steamboats. Sporadic²²⁵ attempts were made in the early days of the nineteenth century both in this country and in America to drive ships by means of screws, both manually and by the medium of steam, some of which were attended with a certain measure of success.153 Yet some time was to elapse before screw propulsion gained recognition. Doubt as to the efficiency of a screw’s action, ignorance as to the shape of the vessel required and as to the best position for the propeller, difficulty in accommodating the early long-stroke steam engine to drive direct an under-water propeller shaft; inertia²²⁶, prejudice and vested interest, all seem to have played a part in delaying the adoption of what, when it did come, was acknowledged to be the only suitable form of steam propulsion for war vessels.
PETTIT SMITH’S PROPELLER

In 1825 a premium²²⁷ was offered by the Admiralty for the best plan of propelling vessels without paddlewheels; and a plan proposed by Commander S. Brown, R.N., was deemed sufficiently promising for trial: a two-bladed screw propeller placed at the bow of a vessel and actuated by a 12-horsepower engine. But though exhibiting advantages this form of the invention did not survive.

236 The history of the screw-propeller may be said to date from 1836. In that year two capable inventors obtained patents: Mr. Francis Pettit Smith and Captain Ericsson. So little attention had, up to that time, been given to the subject that the two proposals “were presented to the public in the character of novelties, and as such they were regarded by the few who had curiosity enough to look at them.” Smith’s patents were for the application of the screw to propel steam vessels by fixing it in a recess or open space formed in the deadwood; and, says Fincham, “the striking and peculiar merit of Mr. Smith’s plan appears to consist, chiefly, in his having chosen the right position for it to work in.” Trials were carried out with Smith’s propeller in a 6-ton boat on the City and Paddington canal, and then between Blackwall and Folkestone, with encouraging success; the boat, encountering heavy weather off the Foreland, demonstrated the advantage derived²²⁸ from the absence of paddlewheels, and showed the new form of propelling machinery to place no limitations on her qualities as a sailing vessel. She returned to Blackwall, having run over 400 miles at a mean speed of 8 knots.

Captain Ericsson, a Swedish army officer who had come to London and established himself as a civil engineer, had a contemporary success with a boat fitted with two large-bladed propellers each 5 feet 3 inches in diameter. So successful was he, indeed, that he invited the Board of Admiralty to take a trip in tow of his novel craft; a trip which had important and unexpected results on the subsequent progress of steam navigation. One summer day in ’37 the Admiralty barge, in which were the Surveyor and three other members of the Board, was towed by Ericsson’s screw steamer from Somerset House to Limehouse and back at a speed of 10 knots. The demonstration²²⁹ was a complete success, and the inventor anticipated some further patronage²³⁰ of his invention. But to his chagrin²³¹ nothing was asked of him, and to his amazement²³² he was subsequently informed that the proposal to propel warships by means of a screw had been pronounced impracticable. Never, perhaps, in the whole history of mechanical progress has so signally wrong a decision been made, never has expert opinion been so mistaken. Engineers and shipbuilders all failed to realize the possibilities of the screw. The naval authorities who, in the face of their personal experience, dismissed the project as impracticable (owing to some anticipated237 difficulties in steering²³³ ships fitted with screws) merely expressed the unanimous opinion of the time. “The engineering corps²³⁵ of the empire were arrayed in opposition²³⁶ to it, alleging²³⁷ that it was constructed on erroneous principles, and full of practical defects, and regarding its failure as too certain to authorize²³⁸ any speculations even of its success. The plan was specially⁵¹ submitted to many distinguished engineers, and was publicly discussed in the scientific journals; and there was no one but the inventor who refused to acquiesce²³⁹ in the truth of the numerous demonstrations²⁴⁰, proving the vast loss of mechanical power which must attend this proposed substitute for the old-fashioned paddlewheel.”154 Yet in five years’ time steamers designed for paddlewheels were being converted to carry screws, and a great screw-propelled liner, the Great Britain, had been launched for the Atlantic traffic!

It was in America, we have seen, that progress in steam navigation was of the greatest interest to the public, and it was by Americans that the disabilities of the paddlewheel were most keenly appreciated. Two witnesses of the trial of Ericsson’s boat saw and admitted the advantages of the new method: Mr. Ogden, an engineer who had been U.S. consul²⁴¹ at Liverpool for some years, and Captain Stockton, U.S.N. The latter appreciated the military advantages of screw propulsion and was soon its enthusiastic advocate. Under his influence and encouragement Ericsson threw up his engagements in London and went to America. “We’ll make your name ring on the Delaware,” said Captain Stockton to him at a dinner in his honour given at Greenwich. The prediction was fulfilled. In the course of time Ericsson saw his propeller applied on a large scale, not only to mercantile craft but in the American navy. Early in ’37 Captain Stockton had ordered an iron vessel to be built by Messrs. Laird, of Birkenhead, and fitted with a screw. In the following year she was launched, and in the spring of ’40, after giving demonstration on the Thames of the great towing power of her propeller, she left for America for service as a tug¹¹² on the big rivers. On this work one of the great advantages of the screw was realized: the immunity²⁴² with which the screw vessel could work in drift ice, when paddlewheel steamers were perforce laid up.

In the meantime, fortunately, Pettit Smith’s successes had not been without their effect on opinion in this country. A238 company was formed to exploit the screw, and a vessel, the Archimedes, was built amid a strange chorus of detraction²⁴³, opposition and ridicule²⁴⁴. She made her trials in October, ’39. Her propeller was at first in the form of a complete convolution of a helical screw of 8-foot pitch and of 5 foot 9 inches diameter; but subsequently this blade was replaced by two, each of which formed half a convolution, with the two halves set at right angles to one another. Comparative trials were ordered by the Admiralty in the following year to test the merits of the Archimedes’ screw as compared with the ordinary paddlewheels applied to her Majesty’s mail packets on the Dover station. The results were inconclusive.155 But a subsequent voyage round the coasts of Great Britain, during which the machinery of the Archimedes was laid open to the inspection²⁴⁵ of the general public, and a later voyage from Plymouth to Oporto which recreated a new record for a steam passage, went far to establish in public estimation the merits of the new propeller. But generally the invention was discouraged. Prejudice and vested interests, rather than a reasoned conservation, seem to have operated to oppose its progress. “A striking instance of prevailing²⁴⁶ disinclination to the screw propeller was shown on the issue of a new edition of the Encyclop?dia Britannica, in which the article on steam navigation contained no notice whatever of the subject.”

But in spite of all prepossessions against it the screw had won a decisive victory over its rival. So striking were the results recorded by the Archimedes, that a decision was made in December, 1840, to change the Great Britain, an Atlantic liner then under construction, from paddlewheel to screw propulsion. In two ways she was a gigantic experiment: she was the first large ship to be built of iron, and it was now proposed to fit her with a screw. Mr. Brunel took all the responsibility for advising the adoption of both these revolutionary features; the result was a splendid testimony²⁴⁷ to his scientific judgment, boldness of enterprise, and “confident reliance on deductions²⁴⁸ from facts ascertained²⁴⁹ on a small scale.”

239 Before the completion of the Great Britain the Admiralty had initiated experiments which were to furnish important information as to the power and efficiency of the screw propeller in its various forms, and to settle beyond cavil²⁵⁰ the question of its superiority over the paddlewheel for the propulsion of warships. The sloop²⁵¹ Rattler, 888 tons and 200 horsepower, was fitted with screw machinery. Several forms of screw were tried during the winter of 1843–4. First the screw as used in the Archimedes was fitted: a screw of 9-foot diameter, 11-foot pitch, and of 5? feet length, consisting of two half-convolutions of a blade upon its axis. Then a screw was tried of the same diameter and pitch but of only 4-foot length; and then the length was again reduced to 3 feet. The effect of cutting down the length was to give an increase of efficiency.156 The screw was again shortened by 2 feet, and finally to 1 foot 3 inches; with each reduction in length the slip diminished and the propulsive efficiency increased. Various other forms of screws were tried, and it was shown that Pettit Smith’s short two-bladed propeller was on the whole the most efficient.

The best form of screw having been determined, it still remained to compare the screw propeller with the paddlewheel. Accordingly the Alecto, a paddlewheel sloop of similar lines to the Rattler, was selected as the protagonist²⁵² of the older form of propulsion, while the Rattler herself represented the screw. Naval opinion was still completely divided on the great question, while in the competing sloops²⁵³ the utmost emulation²⁵⁴ existed, each captain advocating his own type of propeller. The speed trials took place, and showed the Rattler to have an undoubted advantage. The paddlewheel, however, laid claim to a superiority in towing power. So a further competition was ordered, as realistic as any, perhaps, in the history of applied science: nothing less than a tug-of-war between Paddle and Screw, those two contending forms of steam propulsion! Lashed²⁵⁵ stern to stern and both steaming ahead full power, one evening in the spring of ’45 the two steamers struggled for mastery. And as Rattler slowly but surely pulled240 over Alecto, the question which had been for years so hotly debated was settled; the superiority of the screw was demonstrated. With the adoption of the screw the problem of disposing the armament was settled. The broadsides and the spaces between decks were once more free to the guns along the entire length; moreover the action of the screw was in complete harmony with that of the sails. With the screw as an auxiliary to sail power, and subsequently with the screw as sole means of propulsion, a change came over the character of the pivot armament. Whereas with the paddlewheel the pivot gun was the chief means of offence, when the screw was introduced the broadside was restored, and though the heavy pivot guns were retained (steam and the pivot gun had become associated ideas), yet by their comparatively limited numbers they became a subordinate element in the total armament.

RATTLER VERSUS²⁵⁶ ALECTO

From an aquatint in the South Kensington Museum

External affairs now lent a spur to screw propulsion. In ’44 the French navy came under the reforming power of the ambitious Prince de Joinville, and from this year onwards the attitude of France to this country became increasingly hostile and menacing. The thoughts of the French were turned toward their navy. No sooner had de Joinville been placed in command than schemes of invasion were bruited²⁵⁷ in this country; and the public viewed with some alarm the altered problems of defence imposed on our fleets by the presence in the enemy’s ports of a steam-propelled navy. Sanguine French patriots²⁵⁸ sought to profit by the advent²⁵⁹ of the new power. A pamphlet appeared in Paris claiming to prove that the establishment of steam navigation afforded France the very means by which she could regain²⁶⁰ her former level of naval strength. The writer, using the same arguments as Colonel Paixhans had used in ’22, reviewed the effect of steam power on the rival navies, and pointed to the Duke of Wellington’s warnings in parliament of the defencelessness of the English coasts and to his statement that if Napoleon had possessed steam power he would have achieved invasion. These cries of alarm, said the writer, should trace for France her line of policy. She should emulate²⁶¹ the wise development of steam propulsion as practised by Great Britain. “We think, England acts; we discuss theories, she pursues application. She creates with activity a redoubtable²⁶² steam force and reduces the number of her sailing ships, whose impotence she recognizes.... Sailing vessels have lost their main power; the employment of241 steamers has reduced them to the subaltern position of the siege artillery in a land army.” The writer praised English policy in the matter of steam development: its wise caution, its reasoned continuity. There had admittedly been some costly²⁶³ deceptions²⁶⁴. Nevertheless the method was to be commended, and France should proceed in a similar manner: by a succession of sample units while steam was still in the experimental stage, by far-sighted single strides, and then by bold and rapid construction of a steam navy which would compete on more even terms with that of her hereditary²⁶⁵ rival.157

Faced with the probability that our rivals would pursue some such progressive and challenging policy as outlined by the pamphleteer, the Admiralty acted rapidly. Before the Rattler trials were complete a decision was made favourable to the screw propeller, and an order was made for its wide application to warships built and building. It was resolved, on the advice of Sir Charles Napier, that the screw should be regarded solely²⁶⁶ as an auxiliary to, and in no way as in competition with, sail power. The Arrogant²⁶⁷ was laid down, the first frigate built for auxiliary steam power; and screws driven by engines of small horse-power were subsequently fitted to other ships with varying degrees of success.

Two important features were specified for all: the machinery was required to be wholly below the water-line, and the screw had to be unshippable. Engines were now required for Block Ships and for sea-going vessels. So the principal engineers of the country were called together and were asked to produce engines in accordance with the bare requirements given them. A variety of designs resulted. From the experience obtained with this machinery two important conclusions were quickly drawn: firstly, that gearing might be altogether dispensed with; secondly, that no complex contrivance was necessary for altering the pitch to enable engines to work advantageously under varying conditions, the efficiency of the screw varying very little whether part of the ship’s velocity were due to sail power or whether it were wholly due to the screw.158

And here it may not be amiss to note, in relation to a nation’s fighting power, the significant position assumed by naval material. In land warfare a rude measure of force could always242 be obtained by a mere²³⁴ counting of heads. At sea man was in future to act, almost entirely, through the medium of the machine.

However we may have deserved the eulogy²⁶⁸ of the French writer in respect of developing the paddlewheel war steamer, the development of screw propulsion in the next decade was marked by a succession of failures and a large outlay²⁶⁹ of money on useless conversions²⁷¹ and on new construction of poor fighting value, most of which could have been avoided. Had our methods been less tentative and more truly scientific the gain would have been undoubtedly²⁷² very great; we should have laid our plans on a firmer basis and arrived at our end, full screw power, by a far less circuitous²⁷³ route than that actually taken. In this respect France had the advantage of us.

Although a decision had been made to maintain the full sail power of our ships and install screw machinery only as an auxiliary motive power, attempts were naturally made to augment²⁷⁴ so far as possible the power exerted by the screw; and within a short time new ships were being fitted with machinery of high power, in an endeavour to make the screw a primary means of propulsion. The results were disappointing. As the power increased difficulties thickened. The weight of the machinery grew to be excessive, the economy of the comparatively fast-running and short-stroke engines proved to be low, and the propulsive efficiency of the screws themselves grew unaccountably smaller and smaller. So poor were the results obtained, indeed, that in the case of a certain ship it was demonstrated that, by taking out the high-power machinery and substituting smaller engines an actual gain in speed was obtained, with the reduced displacement. The first screw ship in which an attempt was made to obtain full power with the screw was the Dauntless, of 1846. Although a frigate of beautiful lines she was considered a comparative failure. It was agreed that, equipped with paddlewheels and armed with guns of larger calibre, she would have constituted a faster and more powerful warship than, with her 580-horse-power engines, her 10 knots of speed, and her 32-pounder guns, she actually was.

Part of the trouble was due to the unsuitability of our ships’ lines for screw propulsion. It has already been noted that, owing to the carriage of heavy weights at their extremities²⁷⁵, war vessels were always given very full bows and sterns. In243 the case of the Rattler, whose records served as a criterion for later designs of screw ships, the lines of the stern were unusually fine: partly, no doubt, in imitation of the Archimedes. Also, since it had been necessary to allow space enough for a long screw to be carried (a screw of a complete convolution was thought possible) the Rattler’s short screw as finally adopted worked at some distance aft of the deadwood, and thus suffered no retarding²⁷⁶ influence from it when under way. But in the case of later ships these advantages did not obtain. They were built with the usual “square tuck,” a bluff form of stern which prevented a free flow of water into the space ahead of the propeller and thus detracted from its efficiency. It was not appreciated at this time that, for efficient action, the screw propeller demands to be supplied with a body of unbroken, non-eddying water for it to act upon, which with the square-cut stern is not obtained. At low speeds, and in the ship to which the screw was fitted as an auxiliary, the effect of the square tuck was not marked. But as power and speed increased its effect became more and more evident; the increase in power gave no proportionate increase in speed; and many, ignorant of the cause, surmised²⁷⁷ that there was a limit to the power which could be transmitted by a screw and that this limit had already been reached. The inefficiency²⁷⁸ of the square tuck was exposed by trials carried out in H.M.S. Dwarf²⁷⁹ at Chatham. As a result of these, future new and converted ships were given as fine a stern as possible.

For several years, however, the policy of the Admiralty remained the same: the screw was regarded solely as an auxiliary. The French, on the other hand, took a less compromising line of action. After waiting for some time and watching our long series of experiments, they convened²⁸⁰ in 1849 a grand Enquête Parliamentaire: a commission which, primed with the latest information as to British naval material, was to decide on what basis of size, number, armament and means of propulsion future French warships should be built. For two years the commission sat sifting²⁸¹ evidence. And then it recommended screw propulsion of the highest power for all new ships, as well as the conversion²⁷⁰ of some existing classes to auxiliary screw power. England had fitted her ships with screws capable of giving them small speed; France must fit hers with screws of greater power. Speed, said the commission, is an element of power. Superior speed is the only means by244 which the English can be fought with a good chance of success. Sails must be secondary, therefore, and full reliance must be placed on the screw. The recommendations of the commission were duly realized. In the following years a powerful force of fast screw battleships, frigates²⁸², transports, and despatch²⁸³ boats was constructed which by ’58 had brought the aggregate²⁸⁴ of the horse-power of the French fleet almost to a level with that of England.

When the Crimean War brought the two navies together as allies in ’54 the full effect of the new policy of the French had not yet been made apparent. Some apprehension²⁸⁵ existed in this country as to the adequacy and efficiency of our navy, when compared directly with that of France. But from then onwards this country became aware of the increasing hostility²⁸⁶ of the French public and government; speeches were made, and letters appeared in the press of both countries, which tended to fan the flames of fear and suspicion.159 It was not till ’58, however, that general attention was drawn to the great strides which the French navy had made in recent years, and to the skilful²⁸⁷ way in which its position, relative to that of its great rival, had been improved. An article entitled “The Navies of England and France” appeared in the Conversations Lexicon²⁸⁸ of Leipsic, and caused a great sensation. Reprinted in book form, with a long analysis and with a mass of information about the French, English and other navies and arsenals,160 this notorious article brought apprehension to a head. Though written by no friendly critic, it was in most respects an accurate presentment of the respective navies and of their condition. The analysis of Hans Busk, while ostensibly exposing its bias²⁸⁹ and its inaccuracies, in effect confirmed the main contentions²⁹⁰ of the German article; in addition his book gave in spectacular columns a summary of the units of the rival navies, which gave food for thought. The article itself professed²⁹¹ to show how much France had benefited by the bold and scientific manner in which she had handled the problem of naval construction since the coming of steam. Other factors were discussed, the forms of ships, the Paixhans system of armament, problems of245 manning and of education; but the factor which had caused the greatest accession of strength to France, by her wise divergence from the English policy, was (according to the critic) steam propulsion. In the case of paddlewheel steamers England, by her unscientific and ruinous experiments, had squandered²⁹² millions of money and produced a series of crank and inefficient war vessels. In the case of screw ships England’s waste of exertions²⁹³ and money was even more surprising; the building of new ships and the conversion of others was carried out at an enormous cost with many galling²⁹⁴ disappointments. The French, on the other hand, took longer to consider the principle of the screw, but then, when their more scientific constructors had completed their investigations and analysed the new power, they acted thoroughly²⁹⁵ and without delay. From all of which the German critic inferred that England had good reason to watch with anxious eye the significant development of strength on the part of her neighbours across the Channel. “We must pronounce,” he concluded, “that with a nearly equal amount of matériel, the French navy surpasses the English in capacity and in command of men. France need feel no hesitation²⁹⁶ in placing herself in comparison with England.... Never was the policy of England so yielding and considerate towards France as at the present day. And then, with respect to the vexed²⁹⁷ question of the invasion, it is certain that Napoleon III has the means of effecting it with greater ease and far greater chance of success than his uncle.”

The means was steam power. But the much-talked-of invasion was never to be attempted. Other events intervened, other developments took place, which reduced the tension between the two great naval powers and removed for an indefinite time the danger, which the Leipsic article disinterestedly²⁹⁸ pointed out, of war under novel and unprecedentedly terrible conditions: with shell guns and wooden unarmoured steam warships.

1 naval   

adj.海军的，军舰的，船的

参考例句：

• He took part in a great naval battle.他参加了一次大海战。
• The harbour is an important naval base.该港是一个重要的海军基地。

2 warfare   

n.战争(状态)；斗争；冲突

参考例句：

• He addressed the audience on the subject of atomic warfare.他向听众演讲有关原子战争的问题。
• Their struggle consists mainly in peasant guerrilla warfare.他们的斗争主要是农民游击战。

3 visualize   

vt.使看得见，使具体化，想象，设想

参考例句：

• I remember meeting the man before but I can't visualize him.我记得以前见过那个人，但他的样子我想不起来了。
• She couldn't visualize flying through space.她无法想像在太空中飞行的景象。

4 warship   

n.军舰，战舰

参考例句：

• He is serving on a warship in the Pacific.他在太平洋海域的一艘军舰上服役。
• The warship was making towards the pier.军舰正驶向码头。

5 ruffle   

v.弄皱，弄乱；激怒，扰乱；n.褶裥饰边

参考例句：

• Don't ruffle my hair.I've just combed it.别把我的头发弄乱了。我刚刚梳好了的。
• You shouldn't ruffle so easily.你不该那么容易发脾气。

6 swell   

vi.膨胀，肿胀；增长，增强

参考例句：

• The waves had taken on a deep swell.海浪汹涌。
• His injured wrist began to swell.他那受伤的手腕开始肿了。

7 oar   

n.桨，橹，划手；v.划行

参考例句：

• The sailors oar slowly across the river.水手们慢慢地划过河去。
• The blade of the oar was bitten off by a shark.浆叶被一条鲨鱼咬掉了。

8 vessel   

n.船舶；容器，器皿；管，导管，血管

参考例句：

• The vessel is fully loaded with cargo for Shanghai.这艘船满载货物驶往上海。
• You should put the water into a vessel.你应该把水装入容器中。

9 latitudes   

纬度

参考例句：

• Latitudes are the lines that go from east to west. 纬线是从东到西的线。
• It was the brief Indian Summer of the high latitudes. 这是高纬度地方的那种短暂的晚秋。

10 ascendancy   

n.统治权，支配力量

参考例句：

• We have had ascendancy over the enemy in the battle.在战斗中我们已占有优势。
• The extremists are gaining ascendancy.极端分子正逐渐占据上风。

11 Mediterranean   

adj.地中海的；地中海沿岸的

参考例句：

• The houses are Mediterranean in character.这些房子都属地中海风格。
• Gibraltar is the key to the Mediterranean.直布罗陀是地中海的要冲。

12 galley   

n.（飞机或船上的）厨房单层甲板大帆船；军舰舰长用的大划艇；

参考例句：

• The stewardess will get you some water from the galley.空姐会从厨房给你拿些水来。
• Visitors can also go through the large galley where crew members got their meals.游客还可以穿过船员们用餐的厨房。

13 ram   

(random access memory)随机存取存储器

参考例句：

• 512k RAM is recommended and 640k RAM is preferred.推荐配置为512K内存，640K内存则更佳。

14 cannon   

n.大炮，火炮；飞机上的机关炮

参考例句：

• The soldiers fired the cannon.士兵们开炮。
• The cannon thundered in the hills.大炮在山间轰鸣。

15 artillery   

n.(军)火炮，大炮；炮兵(部队)

参考例句：

• This is a heavy artillery piece.这是一门重炮。
• The artillery has more firepower than the infantry.炮兵火力比步兵大。

16 attained   

（通常经过努力）实现( attain的过去式和过去分词 )； 达到； 获得； 达到（某年龄、水平、状况）

参考例句：

• She has attained the degree of Master of Arts. 她已获得文学硕士学位。
• Lu Hsun attained a high position in the republic of letters. 鲁迅在文坛上获得崇高的地位。

17 sufficiently   

adv.足够地，充分地

参考例句：

• It turned out he had not insured the house sufficiently.原来他没有给房屋投足保险。
• The new policy was sufficiently elastic to accommodate both views.新政策充分灵活地适用两种观点。

18 adversary   

adj.敌手，对手

参考例句：

• He saw her as his main adversary within the company.他将她视为公司中主要的对手。
• They will do anything to undermine their adversary's reputation.他们会不择手段地去损害对手的名誉。

19 oars   

n.桨，橹( oar的名词复数 )；划手v.划（行）( oar的第三人称单数 )

参考例句：

• He pulled as hard as he could on the oars. 他拼命地划桨。
• The sailors are bending to the oars. 水手们在拼命地划桨。 来自《简明英汉词典》

20 incompatible   

adj.不相容的，不协调的，不相配的

参考例句：

• His plan is incompatible with my intent.他的计划与我的意图不相符。
• Speed and safety are not necessarily incompatible.速度和安全未必不相容。

21 irreconcilable   

adj.（指人）难和解的，势不两立的

参考例句：

• These practices are irreconcilable with the law of the Church.这种做法与教规是相悖的。
• These old concepts are irreconcilable with modern life.这些陈旧的观念与现代生活格格不入。

22 oared   

adj.有桨的v.划（行）( oar的过去式和过去分词 )

参考例句：

• He oared himself to the other side of the big river. 他划到大河的彼岸。 来自辞典例句
• A four-oared galley is hovering about. 一艘四桨的小艇，在四下游弋。 来自辞典例句

23 galleys   

n.平底大船，战舰( galley的名词复数 )；（船上或航空器上的）厨房

参考例句：

• Other people had drowned at sea since galleys swarmed with painted sails. 自从布满彩帆的大船下海以来，别的人曾淹死在海里。 来自辞典例句
• He sighed for the galleys, with their infamous costume. 他羡慕那些穿着囚衣的苦工。 来自辞典例句

24 stark   

adj.荒凉的；严酷的；完全的；adv.完全地

参考例句：

• The young man is faced with a stark choice.这位年轻人面临严峻的抉择。
• He gave a stark denial to the rumor.他对谣言加以完全的否认。

25 vessels   

n.血管( vessel的名词复数 )；船；容器；（具有特殊品质或接受特殊品质的）人

参考例句：

• The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
• All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》

26 plied   

v.使用（工具）( ply的过去式和过去分词 )；经常供应（食物、饮料）；固定往来；经营生意

参考例句：

• They plied me with questions about my visit to England. 他们不断地询问我的英国之行。 来自《简明英汉词典》
• They plied us with tea and cakes. 他们一个劲儿地让我们喝茶、吃糕饼。 来自《简明英汉词典》

27 converging   

adj.收敛[缩]的，会聚的，趋同的v.（线条、运动的物体等）会于一点( converge的现在分词 )；（趋于）相似或相同；人或车辆汇集；聚集

参考例句：

• Plants had gradually evolved along diverging and converging pathways. 植物是沿着趋异和趋同两种途径逐渐演化的。 来自辞典例句
• This very slowly converging series was known to Leibniz in 1674. 这个收敛很慢的级数是莱布尼茨在1674年得到的。 来自辞典例句

28 risky   

adj.有风险的，冒险的

参考例句：

• It may be risky but we will chance it anyhow.这可能有危险，但我们无论如何要冒一冒险。
• He is well aware how risky this investment is.他心里对这项投资的风险十分清楚。

29 ply   

v.(搬运工等)等候顾客，弯曲

参考例句：

• Taxis licensed to ply for hire at the railway station.许可计程车在火车站候客。
• Ferryboats ply across the English Channel.渡船定期往返于英吉利海峡。

30 detriment   

n.损害；损害物，造成损害的根源

参考例句：

• Smoking is a detriment to one's health.吸烟危害健康。
• His lack of education is a serious detriment to his career.他的未受教育对他的事业是一种严重的妨碍。

31 primitive   

adj.原始的；简单的；n.原(始)人，原始事物

参考例句：

• It is a primitive instinct to flee a place of danger.逃离危险的地方是一种原始本能。
• His book describes the march of the civilization of a primitive society.他的著作描述了一个原始社会的开化过程。

32 treatise   

n.专著；(专题)论文

参考例句：

• The doctor wrote a treatise on alcoholism.那位医生写了一篇关于酗酒问题的论文。
• This is not a treatise on statistical theory.这不是一篇有关统计理论的论文。

33 treatises   

n.专题著作，专题论文，专著( treatise的名词复数 )

参考例句：

• Many treatises in different languages have been published on pigeons. 关于鸽类的著作，用各种文字写的很多。 来自辞典例句
• Many other treatises incorporated the new rigor. 许多其它的专题论文体现了新的严密性。 来自辞典例句

34 sketched   

v.草拟（sketch的过去式与过去分词形式）

参考例句：

• The historical article sketched the major events of the decade. 这篇有关历史的文章概述了这十年中的重大事件。 来自《简明英汉词典》
• He sketched the situation in a few vivid words. 他用几句生动的语言简述了局势。 来自《现代汉英综合大词典》

35 automobile   

n.汽车，机动车

参考例句：

• He is repairing the brake lever of an automobile.他正在修理汽车的刹车杆。
• The automobile slowed down to go around the curves in the road.汽车在路上转弯时放慢了速度。

36 inversion   

n.反向，倒转，倒置

参考例句：

• But sometimes there is an unusual weather condition called a temperature inversion.但有时会有一种被称作“温度逆增”的不平常的天气状态。
• And finally,we made a discussion on the problems in the cooperative inversion.最后，对联合反演中存在的问题进行了讨论。

37 distinguished   

adj.卓越的，杰出的，著名的

参考例句：

• Elephants are distinguished from other animals by their long noses.大象以其长长的鼻子显示出与其他动物的不同。
• A banquet was given in honor of the distinguished guests.宴会是为了向贵宾们致敬而举行的。

38 barges   

驳船( barge的名词复数 )

参考例句：

• The tug is towing three barges. 那只拖船正拖着三只驳船。
• There were plenty of barges dropping down with the tide. 有不少驳船顺流而下。

39 barge   

n.平底载货船，驳船

参考例句：

• The barge was loaded up with coal.那艘驳船装上了煤。
• Carrying goods by train costs nearly three times more than carrying them by barge.通过铁路运货的成本比驳船运货成本高出近3倍。

40 navigate   

v.航行，飞行；导航，领航

参考例句：

• He was the first man to navigate the Atlantic by air.他是第一个飞越大西洋的人。
• Such boats can navigate on the Nile.这种船可以在尼罗河上航行。

41 motive   

n.动机，目的；adv.发动的，运动的

参考例句：

• The police could not find a motive for the murder.警察不能找到谋杀的动机。
• He had some motive in telling this fable.他讲这寓言故事是有用意的。

42 secondly   

adv.第二，其次

参考例句：

• Secondly,use your own head and present your point of view.第二，动脑筋提出自己的见解。
• Secondly it is necessary to define the applied load.其次，需要确定所作用的载荷。

43 utilize   

vt.使用，利用

参考例句：

• The cook will utilize the leftover ham bone to make soup.厨师要用吃剩的猪腿骨做汤。
• You must utilize all available resources.你必须利用一切可以得到的资源。

44 apparatus   

n.装置，器械；器具，设备

参考例句：

• The school's audio apparatus includes films and records.学校的视听设备包括放映机和录音机。
• They had a very refined apparatus.他们有一套非常精良的设备。

45 axis   

n.轴，轴线，中心线；坐标轴，基准线

参考例句：

• The earth's axis is the line between the North and South Poles.地轴是南北极之间的线。
• The axis of a circle is its diameter.圆的轴线是其直径。

46 applied   

adj.应用的；v.应用，适用

参考例句：

• She plans to take a course in applied linguistics.她打算学习应用语言学课程。
• This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。

47 reconstruction   

n.重建，再现，复原

参考例句：

• The country faces a huge task of national reconstruction following the war.战后，该国面临着重建家园的艰巨任务。
• In the period of reconstruction,technique decides everything.在重建时期，技术决定一切。

48 shipwright   

n.造船工人

参考例句：

• His dream is to be a shipwright.他的梦想是成为一名造船者。
• The daughter of a shipwright in the Royal Navy,Elizabeth Marsh had her first sailing adventure as she travelled in her mother's womb from Jamaica to England in 1735.1735年在从牙买加开往英格兰的船上，伊莉莎白·马什，这位英国皇家海军部队造船匠的女儿在母亲的肚中经历了她第一次的航海远行。

49 pivot   

v.在枢轴上转动；装枢轴，枢轴；adj.枢轴的

参考例句：

• She is the central pivot of creation and represents the feminine aspect in all things.她是创造的中心枢轴，表现出万物的女性面貌。
• If a spring is present,the hand wheel will pivot on the spring.如果有弹簧，手轮的枢轴会装在弹簧上。

50 pivoting   

n.绕轴旋转，绕公共法线旋转v.（似）在枢轴上转动( pivot的现在分词 )；把…放在枢轴上；以…为核心，围绕（主旨）展开

参考例句：

• Here is a neat YouTube video showing the Gyro's pivoting mechanism. 这里是一个整洁的YouTube视频显示陀螺仪的旋转机制。 来自互联网
• Dart pivoting is widely used in the gannent pattern design. 省道转移的原理在服装纸样设计中应用十分广泛。 来自互联网

51 specially   

adv.特定地；特殊地；明确地

参考例句：

• They are specially packaged so that they stack easily.它们经过特别包装以便于堆放。
• The machine was designed specially for demolishing old buildings.这种机器是专为拆毁旧楼房而设计的。

52 rotary   

adj.(运动等)旋转的；轮转的；转动的

参考例句：

• The central unit is a rotary drum.核心设备是一个旋转的滚筒。
• A rotary table helps to optimize the beam incidence angle.一张旋转的桌子有助于将光线影响之方式角最佳化。

53 affixed   

adj.[医]附着的，附着的v.附加( affix的过去式和过去分词 )；粘贴；加以；盖（印章）

参考例句：

• The label should be firmly affixed to the package. 这张标签应该牢牢地贴在包裹上。
• He affixed the sign to the wall. 他将标记贴到墙上。 来自《简明英汉词典》

54 velocity   

n.速度，速率

参考例句：

• Einstein's theory links energy with mass and velocity of light.爱因斯坦的理论把能量同质量和光速联系起来。
• The velocity of light is about 300000 kilometres per second.光速约为每秒300000公里。

55 atmospheric   

adj.大气的，空气的；大气层的；大气所引起的

参考例句：

• Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
• Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。

56 speculations   

n.投机买卖( speculation的名词复数 )；思考；投机活动；推断

参考例句：

• Your speculations were all quite close to the truth. 你的揣测都很接近于事实。 来自《现代英汉综合大词典》
• This possibility gives rise to interesting speculations. 这种可能性引起了有趣的推测。 来自《用法词典》

57 conjecture   

n./v.推测，猜测

参考例句：

• She felt it no use to conjecture his motives.她觉得猜想他的动机是没有用的。
• This conjecture is not supported by any real evidence.这种推测未被任何确切的证据所证实。

58 premier   

adj.首要的；n.总理，首相

参考例句：

• The Irish Premier is paying an official visit to Britain.爱尔兰总理正在对英国进行正式访问。
• He requested that the premier grant him an internview.他要求那位总理接见他一次。

59 mechanism   

n.机械装置；机构，结构

参考例句：

• The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
• The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。

60 meddle   

v.干预，干涉，插手

参考例句：

• I hope he doesn't try to meddle in my affairs.我希望他不来干预我的事情。
• Do not meddle in things that do not concern you.别参与和自己无关的事。

61 judgment   

n.审判；判断力，识别力，看法，意见

参考例句：

• The chairman flatters himself on his judgment of people.主席自认为他审视人比别人高明。
• He's a man of excellent judgment.他眼力过人。

62 maritime   

adj.海的，海事的，航海的，近海的，沿海的

参考例句：

• Many maritime people are fishermen.许多居于海滨的人是渔夫。
• The temperature change in winter is less in maritime areas.冬季沿海的温差较小。

63 vertically   

adv.垂直地

参考例句：

• Line the pages for the graph both horizontally and vertically.在这几页上同时画上横线和竖线，以便制作图表。
• The human brain is divided vertically down the middle into two hemispheres.人脑从中央垂直地分为两半球。

64 vertical   

adj.垂直的，顶点的，纵向的；n.垂直物，垂直的位置

参考例句：

• The northern side of the mountain is almost vertical.这座山的北坡几乎是垂直的。
• Vertical air motions are not measured by this system.垂直气流的运动不用这种系统来测量。

65 rotation   

n.旋转；循环，轮流

参考例句：

• Crop rotation helps prevent soil erosion.农作物轮作有助于防止水土流失。
• The workers in this workshop do day and night shifts in weekly rotation.这个车间的工人上白班和上夜班每周轮换一次。

66 incurred   

[医]招致的，遭受的； incur的过去式

参考例句：

• She had incurred the wrath of her father by marrying without his consent 她未经父亲同意就结婚，使父亲震怒。
• We will reimburse any expenses incurred. 我们将付还所有相关费用。

67 previously   

adv.以前，先前（地）

参考例句：

• The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
• Let me digress for a moment and explain what had happened previously.让我岔开一会儿，解释原先发生了什么。

68 sanguine   

adj.充满希望的，乐观的，血红色的

参考例句：

• He has a sanguine attitude to life.他对于人生有乐观的看法。
• He is not very sanguine about our chances of success.他对我们成功的机会不太乐观。

69 obstructed   

阻塞( obstruct的过去式和过去分词 )； 堵塞； 阻碍； 阻止

参考例句：

• Tall trees obstructed his view of the road. 有大树挡着，他看不到道路。
• The Irish and Bristol Channels were closed or grievously obstructed. 爱尔兰海峡和布里斯托尔海峡或遭受封锁，或受到了严重阻碍。

70 shipping   

n.船运（发货，运输，乘船）

参考例句：

• We struck a bargain with an American shipping firm.我们和一家美国船运公司谈成了一笔生意。
• There's a shipping charge of ￡5 added to the price.价格之外另加五英镑运输费。

71 crutched   

用拐杖支持的，有丁字形柄的，有支柱的

参考例句：

72 detailed   

adj.详细的，详尽的，极注意细节的，完全的

参考例句：

• He had made a detailed study of the terrain.他对地形作了缜密的研究。
• A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。

73 plying   

v.使用（工具）( ply的现在分词 )；经常供应（食物、饮料）；固定往来；经营生意

参考例句：

• All manner of hawkers and street sellers were plying their trade. 形形色色的沿街小贩都在做着自己的买卖。 来自《简明英汉词典》
• It was rather Mrs. Wang who led the conversation, plying Miss Liu with questions. 倒是汪太太谈锋甚健，向刘小姐问长问短。 来自汉英文学 - 围城

74 hulls   

船体( hull的名词复数 )； 船身； 外壳； 豆荚

参考例句：

• Hulls may be removed by aspiration on screens. 脱下的种皮，可由筛子上的气吸装置吸除。
• When their object is attained they fall off like empty hulls from the kernel. 当他们的目的达到以后，他们便凋谢零落，就象脱却果实的空壳一样。

75 hull   

n.船身；(果、实等的)外壳；vt.去(谷物等)壳

参考例句：

• The outer surface of ship's hull is very hard.船体的外表面非常坚硬。
• The boat's hull has been staved in by the tremendous seas.小船壳让巨浪打穿了。

76 dubbed   

v.给…起绰号( dub的过去式和过去分词 )；把…称为；配音；复制

参考例句：

• Mathematics was once dubbed the handmaiden of the sciences. 数学曾一度被视为各门科学的基础。
• Is the movie dubbed or does it have subtitles? 这部电影是配音的还是打字幕的？ 来自《简明英汉词典》

77 advancement   

n.前进，促进，提升

参考例句：

• His new contribution to the advancement of physiology was well appreciated.他对生理学发展的新贡献获得高度赞赏。
• The aim of a university should be the advancement of learning.大学的目标应是促进学术。

78 piston   

n.活塞

参考例句：

• They use a piston engine instead.他们改用活塞发动机。
• The piston moves by steam pressure.活塞在蒸汽压力下运动。

79 machinery   

n.(总称)机械，机器；机构

参考例句：

• Has the machinery been put up ready for the broadcast?广播器材安装完毕了吗？
• Machinery ought to be well maintained all the time.机器应该随时注意维护。

80 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

81 reciprocating   

adj.往复的；来回的；交替的；摆动的v.报答，酬答( reciprocate的现在分词 )；（机器的部件）直线往复运动

参考例句：

• Dynamic loading is produced by seismic forces, non-steady wind, blast, reciprocating machinery. 动荷载是由于地震力、不稳定的风、冲击波，往复式机器所产生。 来自辞典例句
• The prime mover may be a gas reciprocating engine. 原动机可能是燃气往复式发动机。 来自辞典例句

82 shaft   

n.(工具的)柄，杆状物

参考例句：

• He was wounded by a shaft.他被箭击中受伤。
• This is the shaft of a steam engine.这是一个蒸汽机主轴。

83 drawn   

v.拖，拉，拔出；adj.憔悴的，紧张的

参考例句：

• All the characters in the story are drawn from life.故事中的所有人物都取材于生活。
• Her gaze was drawn irresistibly to the scene outside.她的目光禁不住被外面的风景所吸引。

84 attaining   

（通常经过努力）实现( attain的现在分词 )； 达到； 获得； 达到（某年龄、水平、状况）

参考例句：

• Jim is halfway to attaining his pilot's licence. 吉姆就快要拿到飞行员执照了。
• By that time she was attaining to fifty. 那时她已快到五十岁了。

85 pointed   

adj.尖的，直截了当的

参考例句：

• He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
• She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。

86 adaptable   

adj.能适应的，适应性强的，可改编的

参考例句：

• He is an adaptable man and will soon learn the new work.他是个适应性很强的人，很快就将学会这种工作。
• The soil is adaptable to the growth of peanuts.这土壤适宜于花生的生长。

87 marine   

adj.海的；海生的；航海的；海事的；n.水兵

参考例句：

• Marine creatures are those which live in the sea. 海洋生物是生存在海里的生物。
• When the war broke out,he volunteered for the Marine Corps.战争爆发时，他自愿参加了海军陆战队。

88 watt   

n.瓦，瓦特

参考例句：

• The invention of the engine is creditable to Watt.发动机的发明归功于瓦特。
• The unit of power is watt.功率的单位是瓦特。

89 virtue   

n.德行，美德；贞操；优点；功效，效力

参考例句：

• He was considered to be a paragon of virtue.他被认为是品德尽善尽美的典范。
• You need to decorate your mind with virtue.你应该用德行美化心灵。

90 brittle   

adj.易碎的；脆弱的；冷淡的；(声音)尖利的

参考例句：

• The pond was covered in a brittle layer of ice.池塘覆盖了一层易碎的冰。
• She gave a brittle laugh.她冷淡地笑了笑。

91 inefficient   

adj.效率低的，无效的

参考例句：

• The inefficient operation cost the firm a lot of money.低效率的运作使该公司损失了许多钱。
• Their communication systems are inefficient in the extreme.他们的通讯系统效率非常差。

92 intervention   

n.介入，干涉，干预

参考例句：

• The government's intervention in this dispute will not help.政府对这场争论的干预不会起作用。
• Many people felt he would be hostile to the idea of foreign intervention.许多人觉得他会反对外来干预。

93 undertakings   

企业( undertaking的名词复数 )； 保证； 殡仪业； 任务

参考例句：

• The principle of diligence and frugality applies to all undertakings. 勤俭节约的原则适用于一切事业。
• Such undertakings require the precise planning and foresight of military operations. 此举要求军事上战役中所需要的准确布置和预见。

94 ingenuity   

n.别出心裁；善于发明创造

参考例句：

• The boy showed ingenuity in making toys.那个小男孩做玩具很有创造力。
• I admire your ingenuity and perseverance.我钦佩你的别出心裁和毅力。

95 miller   

n.磨坊主

参考例句：

• Every miller draws water to his own mill.磨坊主都往自己磨里注水。
• The skilful miller killed millions of lions with his ski.技术娴熟的磨坊主用雪橇杀死了上百万头狮子。

96 forth   

adv.向前；向外，往外

参考例句：

• The wind moved the trees gently back and forth.风吹得树轻轻地来回摇晃。
• He gave forth a series of works in rapid succession.他很快连续发表了一系列的作品。

97 insufficient   

adj.(for，of)不足的，不够的

参考例句：

• There was insufficient evidence to convict him.没有足够证据给他定罪。
• In their day scientific knowledge was insufficient to settle the matter.在他们的时代，科学知识还不能足以解决这些问题。

98 delightfully   

大喜，欣然

参考例句：

• The room is delightfully appointed. 这房子的设备令人舒适愉快。 来自《现代汉英综合大词典》
• The evening is delightfully cool. 晚间凉爽宜人。 来自《现代汉英综合大词典》

99 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

100 cylinder   

n.圆筒，柱(面)，汽缸

参考例句：

• What's the volume of this cylinder?这个圆筒的体积有多少？
• The cylinder is getting too much gas and not enough air.汽缸里汽油太多而空气不足。

101 ornamental   

adj.装饰的；作装饰用的；n.装饰品；观赏植物

参考例句：

• The stream was dammed up to form ornamental lakes.溪流用水坝拦挡起来,形成了装饰性的湖泊。
• The ornamental ironwork lends a touch of elegance to the house.铁艺饰件为房子略添雅致。

102 determined   

adj.坚定的；有决心的

参考例句：

• I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
• He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。

103 replica   

n.复制品

参考例句：

• The original conservatory has been rebuilt in replica.温室已按原样重建。
• The young artist made a replica of the famous painting.这位年轻的画家临摹了这幅著名的作品。

104 ERECTED   

adj. 直立的，竖立的，笔直的 vt. 使 ... 直立，建立

参考例句：

• A monument to him was erected in St Paul's Cathedral. 在圣保罗大教堂为他修了一座纪念碑。
• A monument was erected to the memory of that great scientist. 树立了一块纪念碑纪念那位伟大的科学家。

105 decided   

adj.决定了的，坚决的；明显的，明确的

参考例句：

• This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
• There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。

106 investigations   

（正式的）调查( investigation的名词复数 )； 侦查； 科学研究； 学术研究

参考例句：

• His investigations were intensive and thorough but revealed nothing. 他进行了深入彻底的调查，但没有发现什么。
• He often sent them out to make investigations. 他常常派他们出去作调查。

107 celebrated   

adj.有名的，声誉卓著的

参考例句：

• He was soon one of the most celebrated young painters in England.不久他就成了英格兰最负盛名的年轻画家之一。
• The celebrated violinist was mobbed by the audience.观众团团围住了这位著名的小提琴演奏家。

108 acting   

n.演戏，行为，假装；adj.代理的，临时的，演出用的

参考例句：

• Ignore her,she's just acting.别理她，她只是假装的。
• During the seventies,her acting career was in eclipse.在七十年代，她的表演生涯黯然失色。

109 recess   

n.短期休息，壁凹（墙上装架子，柜子等凹处）

参考例句：

• The chairman of the meeting announced a ten-minute recess.会议主席宣布休会10分钟。
• Parliament was hastily recalled from recess.休会的议员被匆匆召回开会。

110 remarkable   

adj.显著的，异常的，非凡的，值得注意的

参考例句：

• She has made remarkable headway in her writing skills.她在写作技巧方面有了长足进步。
• These cars are remarkable for the quietness of their engines.这些汽车因发动机没有噪音而不同凡响。

111 envisaged   

想像，设想( envisage的过去式和过去分词 )

参考例句：

• He envisaged an old age of loneliness and poverty. 他面对着一个孤独而贫困的晚年。
• Henry Ford envisaged an important future for the motor car. 亨利·福特为汽车设想了一个远大前程。

112 tug   

v.用力拖(或拉)；苦干；n.拖；苦干；拖船

参考例句：

• We need to tug the car round to the front.我们需要把那辆车拉到前面。
• The tug is towing three barges.那只拖船正拖着三只驳船。

113 tugs   

n.猛拉( tug的名词复数 )；猛拖；拖船v.用力拉，使劲拉，猛扯( tug的第三人称单数 )

参考例句：

• The raucous sirens of the tugs came in from the river. 河上传来拖轮发出的沙哑的汽笛声。 来自辞典例句
• As I near the North Tower, the wind tugs at my role. 当我接近北塔的时候，风牵动着我的平衡杆。 来自辞典例句

114 realization   

n.实现；认识到，深刻了解

参考例句：

• We shall gladly lend every effort in our power toward its realization.我们将乐意为它的实现而竭尽全力。
• He came to the realization that he would never make a good teacher.他逐渐认识到自己永远不会成为好老师。

115 persistent   

adj.坚持不懈的，执意的；持续的

参考例句：

• Albert had a persistent headache that lasted for three days.艾伯特连续头痛了三天。
• She felt embarrassed by his persistent attentions.他不时地向她大献殷勤，使她很难为情。

116 geographical   

adj.地理的；地区(性)的

参考例句：

• The current survey will have a wider geographical spread.当前的调查将在更广泛的地域范围內进行。
• These birds have a wide geographical distribution.这些鸟的地理分布很广。

117 relatively   

adv.比较...地，相对地

参考例句：

• The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
• The operation was relatively painless.手术相对来说不痛。

118 dismantled   

拆开( dismantle的过去式和过去分词 )； 拆卸； 废除； 取消

参考例句：

• The plant was dismantled of all its equipment and furniture. 这家工厂的设备和家具全被拆除了。
• The Japanese empire was quickly dismantled. 日本帝国很快被打垮了。

119 ponderous   

adj.沉重的，笨重的，(文章)冗长的

参考例句：

• His steps were heavy and ponderous.他的步伐沉重缓慢。
• It was easy to underestimate him because of his occasionally ponderous manner.由于他偶尔现出的沉闷的姿态，很容易使人小看了他。

120 propeller   

n.螺旋桨，推进器

参考例句：

• The propeller started to spin around.螺旋桨开始飞快地旋转起来。
• A rope jammed the boat's propeller.一根绳子卡住了船的螺旋桨。

121 aquatic   

adj.水生的，水栖的

参考例句：

• Aquatic sports include swimming and rowing.水上运动包括游泳和划船。
• We visited an aquatic city in Italy.我们在意大利访问过一个水上城市。

122 originality   

n.创造力，独创性；新颖

参考例句：

• The name of the game in pop music is originality.流行音乐的本质是独创性。
• He displayed an originality amounting almost to genius.他显示出近乎天才的创造性。

123 illustrated   

adj. 有插图的，列举的 动词illustrate的过去式和过去分词

参考例句：

• His lecture was illustrated with slides taken during the expedition. 他在讲演中使用了探险时拍摄到的幻灯片。
• The manufacturing Methods: Will be illustrated in the next chapter. 制作方法将在下一章说明。

124 interfered   

v.干预( interfere的过去式和过去分词 )；调停；妨碍；干涉

参考例句：

• Complete absorption in sports interfered with his studies. 专注于运动妨碍了他的学业。 来自《简明英汉词典》
• I am not going to be interfered with. 我不想别人干扰我的事情。 来自《简明英汉词典》

125 brace   

n. 支柱,曲柄,大括号; v. 绷紧,顶住,(为困难或坏事)做准备

参考例句：

• My daughter has to wear a brace on her teeth. 我的女儿得戴牙套以矫正牙齿。
• You had better brace yourself for some bad news. 有些坏消息,你最好做好准备。

126 perpendicular   

adj.垂直的，直立的；n.垂直线，垂直的位置

参考例句：

• The two lines of bones are set perpendicular to one another.这两排骨头相互垂直。
• The wall is out of the perpendicular.这墙有些倾斜。

127 utilized   

v.利用，使用( utilize的过去式和过去分词 )

参考例句：

• In the19th century waterpower was widely utilized to generate electricity. 在19世纪人们大规模使用水力来发电。 来自《简明英汉词典》
• The empty building can be utilized for city storage. 可以利用那栋空建筑物作城市的仓库。 来自《简明英汉词典》

128 Vogue   

n.时髦，时尚；adj.流行的

参考例句：

• Flowery carpets became the vogue.花卉地毯变成了时髦货。
• Short hair came back into vogue about ten years ago.大约十年前短发又开始流行起来了。

129 devoted   

adj.忠诚的，忠实的，热心的，献身于...的

参考例句：

• He devoted his life to the educational cause of the motherland.他为祖国的教育事业贡献了一生。
• We devoted a lengthy and full discussion to this topic.我们对这个题目进行了长时间的充分讨论。

130 promising   

adj.有希望的，有前途的

参考例句：

• The results of the experiments are very promising.实验的结果充满了希望。
• We're trying to bring along one or two promising young swimmers.我们正设法培养出一两名有前途的年轻游泳选手。

131 propulsive   

adj.推进的

参考例句：

• The fish uses its tail fins for propulsive force throgh the water.鱼靠尾鳍在水中前进。
• Interest in jet propulsive force was now growing at the Air Ministry.航空部对喷气推进的兴趣正在增加。

132 influential   

adj.有影响的，有权势的

参考例句：

• He always tries to get in with the most influential people.他总是试图巴结最有影响的人物。
• He is a very influential man in the government.他在政府中是个很有影响的人物。

133 mutual   

adj.相互的，彼此的；共同的，共有的

参考例句：

• We must pull together for mutual interest.我们必须为相互的利益而通力合作。
• Mutual interests tied us together.相互的利害关系把我们联系在一起。

134 chancellor   

n.(英)大臣；法官；(德、奥)总理；大学校长

参考例句：

• They submitted their reports to the Chancellor yesterday.他们昨天向财政大臣递交了报告。
• He was regarded as the most successful Chancellor of modern times.他被认为是现代最成功的财政大臣。

135 accrue   

v.(利息等)增大，增多

参考例句：

• Ability to think will accrue to you from good habits of study.思考能力将因良好的学习习惯而自然增强。
• Money deposited in banks will accrue to us with interest.钱存在银行，利息自生。

136 partnership   

n.合作关系，伙伴关系

参考例句：

• The company has gone into partnership with Swiss Bank Corporation.这家公司已经和瑞士银行公司建立合作关系。
• Martin has taken him into general partnership in his company.马丁已让他成为公司的普通合伙人。

137 promptly   

adv.及时地，敏捷地

参考例句：

• He paid the money back promptly.他立即还了钱。
• She promptly seized the opportunity his absence gave her.她立即抓住了因他不在场给她创造的机会。

138 sketches   

n.草图( sketch的名词复数 )；素描；速写；梗概

参考例句：

• The artist is making sketches for his next painting. 画家正为他的下一幅作品画素描。
• You have to admit that these sketches are true to life. 你得承认这些素描很逼真。 来自《简明英汉词典》

139 brass   

n.黄铜；黄铜器，铜管乐器

参考例句：

• Many of the workers play in the factory's brass band.许多工人都在工厂铜管乐队中演奏。
• Brass is formed by the fusion of copper and zinc.黄铜是通过铜和锌的熔合而成的。

140 gleaned   

v.一点点地收集（资料、事实）( glean的过去式和过去分词 )；（收割后）拾穗

参考例句：

• These figures have been gleaned from a number of studies. 这些数据是通过多次研究收集得来的。
• A valuable lesson may be gleaned from it by those who have eyes to see. 明眼人可从中记取宝贵的教训。 来自《现代汉英综合大词典》

141 steamship   

n.汽船，轮船

参考例句：

• The return may be made on the same steamship.可乘同一艘汽船当天回来。
• It was so foggy that the steamship almost ran down a small boat leaving the port.雾很大，汽艇差点把一只正在离港的小船撞沉。

142 divergence   

n.分歧，岔开

参考例句：

• There is no sure cure for this transatlantic divergence.没有什么灵丹妙药可以消除大西洋两岸的分歧。
• In short,it was an age full of conflicts and divergence of values.总之，这一时期是矛盾与价值观分歧的时期。

143 perpetuated   

vt.使永存（perpetuate的过去式与过去分词形式）

参考例句：

• This system perpetuated itself for several centuries. 这一制度维持了几个世纪。
• I never before saw smile caught like that, and perpetuated. 我从来没有看见过谁的笑容陷入这样的窘况，而且持续不变。 来自辞典例句

144 legitimately   

ad.合法地；正当地，合理地

参考例句：

• The radio is legitimately owned by the company. 该电台为这家公司所合法拥有。
• She looked for nothing save what might come legitimately and without the appearance of special favour. 她要的并不是男人们的额外恩赐，而是合法正当地得到的工作。 来自英汉文学 - 嘉莉妹妹

145 utilitarian   

adj.实用的，功利的

参考例句：

• On the utilitarian side American education has outstridden the rest of the world.在实用方面美国教育已超越世界各国。
• A good cloth coat is more utilitarian than a fur one.一件优质的布外衣要比一件毛皮外衣更有用。

146 opprobrium   

n.耻辱，责难

参考例句：

• The opprobrium and enmity he incurred were caused by his outspoken brashness.他招致的轻蔑和敌意是由于他出言过于粗率而造成的。
• That drunkard was the opprobrium of our community.那个酒鬼是我们社区里可耻的人物。

147 boiler   

n.锅炉；煮器(壶，锅等)

参考例句：

• That boiler will not hold up under pressure.那种锅炉受不住压力。
• This new boiler generates more heat than the old one.这个新锅炉产生的热量比旧锅炉多。

148 galaxy   

n.星系；银河系；一群(杰出或著名的人物)

参考例句：

• The earth is one of the planets in the Galaxy.地球是银河系中的星球之一。
• The company has a galaxy of talent.该公司拥有一批优秀的人才。

149 tapering   

adj.尖端细的

参考例句：

• Interest in the scandal seems to be tapering off. 人们对那件丑闻的兴趣似乎越来越小了。
• Nonproductive expenditures keep tapering down. 非生产性开支一直在下降。

150 promenade   

n./v.散步

参考例句：

• People came out in smarter clothes to promenade along the front.人们穿上更加时髦漂亮的衣服，沿着海滨散步。
• We took a promenade along the canal after Sunday dinner.星期天晚饭后我们沿着运河散步。

151 cylinders   

n.圆筒( cylinder的名词复数 )；圆柱；汽缸；（尤指用作容器的）圆筒状物

参考例句：

• They are working on all cylinders to get the job finished. 他们正在竭尽全力争取把这工作干完。 来自《简明英汉词典》
• That jeep has four cylinders. 那辆吉普车有4个汽缸。 来自《简明英汉词典》

152 draught   

n.拉，牵引，拖；一网（饮，吸，阵)；顿服药量，通风；v.起草，设计

参考例句：

• He emptied his glass at one draught.他将杯中物一饮而尽。
• It's a pity the room has no north window and you don't get a draught.可惜这房间没北窗，没有过堂风。

153 projectiles   

n.抛射体( projectile的名词复数 )；（炮弹、子弹等）射弹，（火箭等）自动推进的武器

参考例句：

• These differences are connected with the strong absorption of the composite projectiles. 这些差别与复杂的入射粒子的强烈吸收有关。 来自辞典例句
• Projectiles became more important because cannons could now fire balls over hundreds or yards. 抛射体变得更加重要，因为人们已能用大炮把炮弹射到几百码的距离之外。 来自辞典例句

154 monstrous   

adj.巨大的；恐怖的；可耻的，丢脸的

参考例句：

• The smoke began to whirl and grew into a monstrous column.浓烟开始盘旋上升，形成了一个巨大的烟柱。
• Your behaviour in class is monstrous!你在课堂上的行为真是丢人！

155 immediate   

adj.立即的；直接的，最接近的；紧靠的

参考例句：

• His immediate neighbours felt it their duty to call.他的近邻认为他们有责任去拜访。
• We declared ourselves for the immediate convocation of the meeting.我们主张立即召开这个会议。

156 stimulated   

a.刺激的

参考例句：

• The exhibition has stimulated interest in her work. 展览增进了人们对她作品的兴趣。
• The award has stimulated her into working still harder. 奖金促使她更加努力地工作。

157 astonishment   

n.惊奇，惊异

参考例句：

• They heard him give a loud shout of astonishment.他们听见他惊奇地大叫一声。
• I was filled with astonishment at her strange action.我对她的奇怪举动不胜惊异。

158 swarm   

n.(昆虫)等一大群；vi.成群飞舞；蜂拥而入

参考例句：

• There is a swarm of bees in the tree.这树上有一窝蜜蜂。
• A swarm of ants are moving busily.一群蚂蚁正在忙碌地搬家。

159 frigate   

n.护航舰，大型驱逐舰

参考例句：

• An enemy frigate bore down on the sloop.一艘敌驱逐舰向这只护航舰逼过来。
• I declare we could fight frigate.我敢说我们简直可以和一艘战舰交战。

160 adjourned   

（使）休会， （使）休庭( adjourn的过去式和过去分词 )

参考例句：

• The court adjourned for lunch. 午餐时间法庭休庭。
• The trial was adjourned following the presentation of new evidence to the court. 新证据呈到庭上后，审讯就宣告暂停。

161 auxiliary   

adj.辅助的，备用的

参考例句：

• I work in an auxiliary unit.我在一家附属单位工作。
• The hospital has an auxiliary power system in case of blackout.这家医院装有备用发电系统以防灯火管制。

162 seaports   

n.海港( seaport的名词复数 )

参考例句：

• Airports have joined seaports as ports of entry for the visiting foreigner. 机场和海港一样成为来访的外国人的入境关口。 来自互联网
• Sanya has 16 seaports, 10 islands and 180km of coastline. 三亚有16个港口、10个海岛和180公里的海岸线。 来自互联网

163 superseded   

[医]被代替的，废弃的

参考例句：

• The theory has been superseded by more recent research. 这一理论已为新近的研究所取代。
• The use of machinery has superseded manual labour. 机器的使用已经取代了手工劳动。

164 steamships   

n.汽船，大轮船( steamship的名词复数 )

参考例句：

• Berths on steamships can be booked a long while in advance. 轮船上的床位可以提前多日预订。 来自《现代汉英综合大词典》
• The sailing ships were superseded by the steamships. 帆船已被汽船所取代。 来自《现代英汉综合大词典》

165 agitate   

vi.(for,against)煽动，鼓动；vt.搅动

参考例句：

• They sent agents to agitate the local people.他们派遣情报人员煽动当地的民众。
• All you need to do is gently agitate the water with a finger or paintbrush.你只需要用手指或刷子轻轻地搅动水。

166 warships   

军舰，战舰( warship的名词复数 )； 舰只

参考例句：

• The enemy warships were disengaged from the battle after suffering heavy casualties. 在遭受惨重伤亡后，敌舰退出了海战。
• The government fitted out warships and sailors for them. 政府给他们配备了战舰和水手。

167 reverberated   

回响，回荡( reverberate的过去式和过去分词 )； 使反响，使回荡，使反射

参考例句：

• Her voice reverberated around the hall. 她的声音在大厅里回荡。
• The roar of guns reverberated in the valley. 炮声响彻山谷。

168 peculiar   

adj.古怪的，异常的；特殊的，特有的

参考例句：

• He walks in a peculiar fashion.他走路的样子很奇特。
• He looked at me with a very peculiar expression.他用一种很奇怪的表情看着我。

169 favourable   

adj.赞成的，称赞的，有利的，良好的，顺利的

参考例句：

• The company will lend you money on very favourable terms.这家公司将以非常优惠的条件借钱给你。
• We found that most people are favourable to the idea.我们发现大多数人同意这个意见。

170 invaluable   

adj.无价的，非常宝贵的，极为贵重的

参考例句：

• A computer would have been invaluable for this job.一台计算机对这个工作的作用会是无法估计的。
• This information was invaluable to him.这个消息对他来说是非常宝贵的。

171 piracy   

n.海盗行为，剽窃，著作权侵害

参考例句：

• The government has already adopted effective measures against piracy.政府已采取有效措施惩治盗版行为。
• They made the place a notorious centre of piracy.他们把这地方变成了臭名昭著的海盗中心。

172 entirely   

ad.全部地，完整地；完全地，彻底地

参考例句：

• The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
• His life was entirely given up to the educational work. 他的一生统统献给了教育工作。

173 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。

174 tugging   

n.牵引感v.用力拉，使劲拉，猛扯( tug的现在分词 )

参考例句：

• Tom was tugging at a button-hole and looking sheepish. 汤姆捏住一个钮扣眼使劲地拉，样子显得很害羞。 来自英汉文学 - 汤姆历险
• She kicked him, tugging his thick hair. 她一边踢他，一边扯着他那浓密的头发。 来自辞典例句

175 steer   

vt.驾驶，为…操舵；引导；vi.驾驶

参考例句：

• If you push the car, I'll steer it.如果你来推车，我就来驾车。
• It's no use trying to steer the boy into a course of action that suits you.想说服这孩子按你的方式行事是徒劳的。

176 depreciating   

v.贬值，跌价，减价( depreciate的现在分词 )；贬低，蔑视，轻视

参考例句：

• Explain how depreciating PP&E is an example of the matching principle. 解释房产、厂房、设备折旧如何体现了配比原则？ 来自互联网
• Explain how depreciating an example of the matching principle. 解释房产、房、备折旧如何体现了配比原则？ 来自互联网

177 supremacy   

n.至上；至高权力

参考例句：

• No one could challenge her supremacy in gymnastics.她是最优秀的体操运动员，无人能胜过她。
• Theoretically,she holds supremacy as the head of the state.从理论上说，她作为国家的最高元首拥有至高无上的权力。

178 utilization   

n.利用，效用

参考例句：

• Computer has found an increasingly wide utilization in all fields.电子计算机已越来越广泛地在各个领域得到应用。
• Modern forms of agricultural utilization,have completely refuted this assumption.现代农业利用形式，完全驳倒了这种想象。

179 minor   

adj.较小(少)的，较次要的；n.辅修学科；vi.辅修

参考例句：

• The young actor was given a minor part in the new play.年轻的男演员在这出新戏里被分派担任一个小角色。
• I gave him a minor share of my wealth.我把小部分财产给了他。

180 schooner   

n.纵帆船

参考例句：

• The schooner was driven ashore.那条帆船被冲上了岸。
• The current was bearing coracle and schooner southward at an equal rate.急流正以同样的速度将小筏子和帆船一起冲向南方。

181 usurp   

vt.篡夺，霸占；vi.篡位

参考例句：

• Their position enabled them to usurp power.他们所处的地位使其得以篡权。
• You must not allow it to usurp a disproportionate share of your interest.你不应让它过多地占据你的兴趣。

182 gales   

龙猫

参考例句：

• I could hear gales of laughter coming from downstairs. 我能听到来自楼下的阵阵笑声。
• This was greeted with gales of laughter from the audience. 观众对此报以阵阵笑声。

183 derive   

v.取得；导出；引申；来自；源自；出自

参考例句：

• We derive our sustenance from the land.我们从土地获取食物。
• We shall derive much benefit from reading good novels.我们将从优秀小说中获得很大好处。

184 sprightly   

adj.愉快的，活泼的

参考例句：

• She is as sprightly as a woman half her age.她跟比她年轻一半的妇女一样活泼。
• He's surprisingly sprightly for an old man.他这把年纪了，还这么精神，真了不起。

185 shipwrights   

n.造船者，修船者( shipwright的名词复数 )

参考例句：

186 utilizing   

v.利用，使用( utilize的现在分词 )

参考例句：

• Utilizing an assembler to produce a machine-language program. 用汇编程序产生机器语言的过程。 来自辞典例句
• The study and use of devices utilizing properties of materials near absolute zero in temperature. 对材料在接近绝对零度时的特性进行研究和利用的学科。 来自辞典例句

187 dispensed   

v.分配( dispense的过去式和过去分词 )；施与；配（药）

参考例句：

• Not a single one of these conditions can be dispensed with. 这些条件缺一不可。 来自《现代汉英综合大词典》
• They dispensed new clothes to the children in the orphanage. 他们把新衣服发给孤儿院的小孩们。 来自《现代英汉综合大词典》

188 destined   

adj.命中注定的；(for)以…为目的地的

参考例句：

• It was destined that they would marry.他们结婚是缘分。
• The shipment is destined for America.这批货物将运往美国。

189 intervals   

n.[军事]间隔( interval的名词复数 )；间隔时间；[数学]区间；（戏剧、电影或音乐会的）幕间休息

参考例句：

• The forecast said there would be sunny intervals and showers. 预报间晴，有阵雨。
• Meetings take place at fortnightly intervals. 每两周开一次会。

190 forerunner   

n.前身，先驱（者），预兆，祖先

参考例句：

• She is a forerunner of the modern women's movement.她是现代妇女运动的先驱。
• Penicillin was the forerunner of modern antibiotics.青霉素是现代抗生素的先导。

191 initiated   

n. 创始人 adj. 新加入的 vt. 开始，创始，启蒙，介绍加入

参考例句：

• He has not yet been thoroughly initiated into the mysteries of computers. 他对计算机的奥秘尚未入门。
• The artist initiated the girl into the art world in France. 这个艺术家介绍这个女孩加入巴黎艺术界。

192 tersely   

adv. 简捷地, 简要地

参考例句：

• Nixon proceeded to respond, mercifully more tersely than Brezhnev. 尼克松开始作出回答了。幸运的是，他讲的比勃列日涅夫简练。
• Hafiz Issail tersely informed me that Israel force had broken the young cease-fire. 哈菲兹·伊斯梅尔的来电简洁扼要，他说以色列部队破坏了刚刚生效的停火。

193 hardy   

adj.勇敢的，果断的，吃苦的；耐寒的

参考例句：

• The kind of plant is a hardy annual.这种植物是耐寒的一年生植物。
• He is a hardy person.他是一个能吃苦耐劳的人。

194 navigated   

v.给（船舶、飞机等）引航，导航( navigate的过去式和过去分词 )；（从海上、空中等）横越；横渡；飞跃

参考例句：

• He navigated the plane through the clouds. 他驾驶飞机穿越云层。 来自《简明英汉词典》
• The ship was navigated by the North Star. 那只船靠北极星来导航。 来自《简明英汉词典》

195 steered   

v.驾驶( steer的过去式和过去分词 )；操纵；控制；引导

参考例句：

• He steered the boat into the harbour. 他把船开进港。
• The freighter steered out of Santiago Bay that evening. 那天晚上货轮驶出了圣地亚哥湾。 来自《简明英汉词典》

196 alleged   

a.被指控的，嫌疑的

参考例句：

• It was alleged that he had taken bribes while in office. 他被指称在任时收受贿赂。
• alleged irregularities in the election campaign 被指称竞选运动中的不正当行为

197 condemned   

adj. 被责难的, 被宣告有罪的 动词condemn的过去式和过去分词

参考例句：

• He condemned the hypocrisy of those politicians who do one thing and say another. 他谴责了那些说一套做一套的政客的虚伪。
• The policy has been condemned as a regressive step. 这项政策被认为是一种倒退而受到谴责。

198 valid   

adj.有确实根据的；有效的；正当的，合法的

参考例句：

• His claim to own the house is valid.他主张对此屋的所有权有效。
• Do you have valid reasons for your absence?你的缺席有正当理由吗？

199 embodied   

v.表现( embody的过去式和过去分词 )；象征；包括；包含

参考例句：

• a politician who embodied the hopes of black youth 代表黑人青年希望的政治家
• The heroic deeds of him embodied the glorious tradition of the troops. 他的英雄事迹体现了军队的光荣传统。 来自《简明英汉词典》

200 monopolized   

v.垄断( monopolize的过去式和过去分词 )；独占；专卖；专营

参考例句：

• Men traditionally monopolized jobs in the printing industry. 在传统上，男人包揽了印刷行业中的所有工作。
• The oil combine monopolized the fuel sales of the country. 这家石油联合企业垄断了这个国家的原油销售。 来自互联网

201 possessed   

adj.疯狂的；拥有的，占有的

参考例句：

• He flew out of the room like a man possessed.他像着了魔似地猛然冲出房门。
• He behaved like someone possessed.他行为举止像是魔怔了。

202 ordnance   

n.大炮，军械

参考例句：

• She worked in an ordnance factory during the war.战争期间她在一家兵工厂工作。
• Shoes and clothing for the army were scarce,ordnance supplies and drugs were scarcer.军队很缺鞋和衣服，武器供应和药品就更少了。

203 stimulus   

n.刺激，刺激物，促进因素，引起兴奋的事物

参考例句：

• Regard each failure as a stimulus to further efforts.把每次失利看成对进一步努力的激励。
• Light is a stimulus to growth in plants.光是促进植物生长的一个因素。

204 unprecedentedly   

adv.空前地

参考例句：

• The National-Day celebration this year was an unprecedentedly great occasion. 今年国庆日庆祝仪式空前盛大。
• "This is undoubtedly a good one," the teacher insisted. "Unprecedentedly good! Just listen -- " 洋教师说，“这文章写得当然好，而且绝妙无比，你们听——” 来自汉英文学 - 散文英译

205 lengthened   

（时间或空间）延长，伸长( lengthen的过去式和过去分词 )

参考例句：

• The afternoon shadows lengthened. 下午影子渐渐变长了。
• He wanted to have his coat lengthened a bit. 他要把上衣放长一些。

206 bluff   

v.虚张声势，用假象骗人；n.虚张声势，欺骗

参考例句：

• His threats are merely bluff.他的威胁仅仅是虚张声势。
• John is a deep card.No one can bluff him easily.约翰是个机灵鬼。谁也不容易欺骗他。

207 displacement   

n.移置，取代，位移，排水量

参考例句：

• They said that time is the feeling of spatial displacement.他们说时间是空间位移的感觉。
• The displacement of all my energy into caring for the baby.我所有精力都放在了照顾宝宝上。

208 compensate   

vt.补偿，赔偿；酬报 vi.弥补；补偿；抵消

参考例句：

• She used her good looks to compensate her lack of intelligence. 她利用她漂亮的外表来弥补智力的不足。
• Nothing can compensate for the loss of one's health. 一个人失去了键康是不可弥补的。

209 alterations   

n.改动( alteration的名词复数 )；更改；变化；改变

参考例句：

• Any alterations should be written in neatly to the left side. 改动部分应书写清晰，插在正文的左侧。 来自《简明英汉词典》
• Gene mutations are alterations in the DNA code. 基因突变是指DNA 密码的改变。 来自《简明英汉词典》

210 accomplished   

adj.有才艺的；有造诣的；达到了的

参考例句：

• Thanks to your help,we accomplished the task ahead of schedule.亏得你们帮忙,我们才提前完成了任务。
• Removal of excess heat is accomplished by means of a radiator.通过散热器完成多余热量的排出。

211 boilers   

锅炉，烧水器，水壶( boiler的名词复数 )

参考例句：

• Even then the boilers often burst or came apart at the seams. 甚至那时的锅炉也经常从焊接处爆炸或裂开。 来自英汉非文学 - 科学史
• The clean coal is sent to a crusher and the boilers. 干净的煤送入破碎机和锅炉。

212 partially   

adv.部分地，从某些方面讲

参考例句：

• The door was partially concealed by the drapes.门有一部分被门帘遮住了。
• The police managed to restore calm and the curfew was partially lifted.警方设法恢复了平静，宵禁部分解除。

213 propellers   

n.螺旋桨，推进器( propeller的名词复数 )

参考例句：

• The water was thrashing and churning about under the propellers. 水在螺旋桨下面打旋、翻滚。 来自辞典例句
• The ship's propellers churned the waves to foam. 轮船的推进器将海浪搅出泡沫。 来自辞典例句

214 modification   

n.修改，改进，缓和，减轻

参考例句：

• The law,in its present form,is unjust;it needs modification.现行的法律是不公正的，它需要修改。
• The design requires considerable modification.这个设计需要作大的修改。

215 cramped   

a.狭窄的

参考例句：

• The house was terribly small and cramped, but the agent described it as a bijou residence. 房子十分狭小拥挤，但经纪人却把它说成是小巧别致的住宅。
• working in cramped conditions 在拥挤的环境里工作

216 radius   

n.半径，半径范围；有效航程，范围，界限

参考例句：

• He has visited every shop within a radius of two miles.周围两英里以内的店铺他都去过。
• We are measuring the radius of the circle.我们正在测量圆的半径。

217 attainment   

n.达到，到达；［常pl.］成就，造诣

参考例句：

• We congratulated her upon her attainment to so great an age.我们祝贺她高寿。
• The attainment of the success is not easy.成功的取得并不容易。

218 specified   

adj.特定的

参考例句：

• The architect specified oak for the wood trim. 那位建筑师指定用橡木做木饰条。
• It is generated by some specified means. 这是由某些未加说明的方法产生的。

219 spacious   

adj.广阔的，宽敞的

参考例句：

• Our yard is spacious enough for a swimming pool.我们的院子很宽敞，足够建一座游泳池。
• The room is bright and spacious.这房间很豁亮。

220 usurped   

篡夺，霸占( usurp的过去式和过去分词 )； 盗用； 篡夺，篡权

参考例句：

• That magazine usurped copyrighted material. 那杂志盗用了版权为他人所有的素材。
• The expression'social engineering'has been usurped by the Utopianist without a shadow of light. “社会工程”这个词已被乌托邦主义者毫无理由地盗用了。

221 surmount   

vt.克服；置于…顶上

参考例句：

• We have many problems to surmount before we can start the project.我们得克服许多困难才能著手做这项工作。
• We are fully confident that we can surmount these difficulties.我们完全相信我们能够克服这些困难。

222 riddle   

n.谜，谜语，粗筛；vt.解谜，给…出谜，筛，检查，鉴定，非难，充满于；vi.出谜

参考例句：

• The riddle couldn't be solved by the child.这个谜语孩子猜不出来。
• Her disappearance is a complete riddle.她的失踪完全是一个谜。

223 adoption   

n.采用，采纳，通过；收养

参考例句：

• An adoption agency had sent the boys to two different families.一个收养机构把他们送给两个不同的家庭。
• The adoption of this policy would relieve them of a tremendous burden.采取这一政策会给他们解除一个巨大的负担。

224 warp   

vt.弄歪，使翘曲，使不正常，歪曲，使有偏见

参考例句：

• The damp wood began to warp.这块潮湿的木材有些翘曲了。
• A steel girder may warp in a fire.钢梁遇火会变弯。

225 sporadic   

adj.偶尔发生的 [反]regular；分散的

参考例句：

• The sound of sporadic shooting could still be heard.仍能听见零星的枪声。
• You know this better than I.I received only sporadic news about it.你们比我更清楚，而我听到的只是零星消息。

226 inertia   

adj.惰性，惯性，懒惰，迟钝

参考例句：

• We had a feeling of inertia in the afternoon.下午我们感觉很懒。
• Inertia carried the plane onto the ground.飞机靠惯性着陆。

227 premium   

n.加付款；赠品；adj.高级的；售价高的

参考例句：

• You have to pay a premium for express delivery.寄快递你得付额外费用。
• Fresh water was at a premium after the reservoir was contaminated.在水库被污染之后，清水便因稀而贵了。

228 derived   

vi.起源；由来；衍生；导出v.得到( derive的过去式和过去分词 )；（从…中）得到获得；源于；（从…中）提取

参考例句：

• Many English words are derived from Latin and Greek. 英语很多词源出于拉丁文和希腊文。 来自《简明英汉词典》
• He derived his enthusiasm for literature from his father. 他对文学的爱好是受他父亲的影响。 来自《简明英汉词典》

229 demonstration   

n.表明，示范，论证，示威

参考例句：

• His new book is a demonstration of his patriotism.他写的新书是他的爱国精神的证明。
• He gave a demonstration of the new technique then and there.他当场表演了这种新的操作方法。

230 patronage   

n.赞助，支援，援助；光顾，捧场

参考例句：

• Though it was not yet noon,there was considerable patronage.虽然时间未到中午，店中已有许多顾客惠顾。
• I am sorry to say that my patronage ends with this.很抱歉，我的赞助只能到此为止。

231 chagrin   

n.懊恼；气愤；委屈

参考例句：

• His increasingly visible chagrin sets up a vicious circle.他的明显的不满引起了一种恶性循环。
• Much to his chagrin,he did not win the race.使他大为懊恼的是他赛跑没获胜。

232 amazement   

n.惊奇，惊讶

参考例句：

• All those around him looked at him with amazement.周围的人都对他投射出惊异的眼光。
• He looked at me in blank amazement.他带着迷茫惊诧的神情望着我。

233 steering   

n.操舵装置

参考例句：

• He beat his hands on the steering wheel in frustration. 他沮丧地用手打了几下方向盘。
• Steering according to the wind, he also framed his words more amicably. 他真会看风使舵，口吻也马上变得温和了。

234 mere   

adj.纯粹的；仅仅，只不过

参考例句：

• That is a mere repetition of what you said before.那不过是重复了你以前讲的话。
• It's a mere waste of time waiting any longer.再等下去纯粹是浪费时间。

235 corps   

n.(通信等兵种的)部队；(同类作的)一组

参考例句：

• The medical corps were cited for bravery in combat.医疗队由于在战场上的英勇表现而受嘉奖。
• When the war broke out,he volunteered for the Marine Corps.战争爆发时，他自愿参加了海军陆战队。

236 opposition   

n.反对，敌对

参考例句：

• The party leader is facing opposition in his own backyard.该党领袖在自己的党內遇到了反对。
• The police tried to break down the prisoner's opposition.警察设法制住了那个囚犯的反抗。

237 alleging   

断言，宣称，辩解( allege的现在分词 )

参考例句：

• His reputation was blemished by a newspaper article alleging he'd evaded his taxes. 由于报上一篇文章声称他曾逃税，他的名誉受到损害。
• This our Peeress declined as unnecessary, alleging that her cousin Thornhill's recommendation would be sufficient. 那位贵人不肯，还说不必，只要有她老表唐希尔保荐就够了。

238 authorize   

v.授权，委任；批准，认可

参考例句：

• He said that he needed to get his supervisor to authorize my refund.他说必须让主管人员批准我的退款。
• Only the President could authorize the use of the atomic bomb.只有总统才能授权使用原子弹。

239 acquiesce   

vi.默许，顺从，同意

参考例句：

• Her parents will never acquiesce in such an unsuitable marriage.她的父母决不会答应这门不相宜的婚事。
• He is so independent that he will never acquiesce.他很有主见，所以绝不会顺从。

240 demonstrations   

证明( demonstration的名词复数 )； 表明； 表达； 游行示威

参考例句：

• Lectures will be interspersed with practical demonstrations. 讲课中将不时插入实际示范。
• The new military government has banned strikes and demonstrations. 新的军人政府禁止罢工和示威活动。

241 consul   

n.领事；执政官

参考例句：

• A consul's duty is to help his own nationals.领事的职责是帮助自己的同胞。
• He'll hold the post of consul general for the United States at Shanghai.他将就任美国驻上海总领事(的职务)。

242 immunity   

n.优惠；免除；豁免，豁免权

参考例句：

• The law gives public schools immunity from taxation.法律免除公立学校的纳税义务。
• He claims diplomatic immunity to avoid being arrested.他要求外交豁免以便避免被捕。

243 detraction   

n.减损；诽谤

参考例句：

• Envy has no other quality But that of detraction from virtue.嫉妒除了损坏美德外，别无可取之处。
• Faced with such detraction,scientists characteristically retort that science,unlike witchcraft,works.面对诋毁，科学家们出于天性给予反驳，宣称科学不是巫术，确实有效。

244 ridicule   

v.讥讽，挖苦；n.嘲弄

参考例句：

• You mustn't ridicule unfortunate people.你不该嘲笑不幸的人。
• Silly mistakes and queer clothes often arouse ridicule.荒谬的错误和古怪的服装常会引起人们的讪笑。

245 inspection   

n.检查，审查，检阅

参考例句：

• On random inspection the meat was found to be bad.经抽查，发现肉变质了。
• The soldiers lined up for their daily inspection by their officers.士兵们列队接受军官的日常检阅。

246 prevailing   

adj.盛行的；占优势的；主要的

参考例句：

• She wears a fashionable hair style prevailing in the city.她的发型是这个城市流行的款式。
• This reflects attitudes and values prevailing in society.这反映了社会上盛行的态度和价值观。

247 testimony   

n.证词；见证，证明

参考例句：

• The testimony given by him is dubious.他所作的证据是可疑的。
• He was called in to bear testimony to what the police officer said.他被传入为警官所说的话作证。

248 deductions   

扣除( deduction的名词复数 )； 结论； 扣除的量； 推演

参考例句：

• Many of the older officers trusted agents sightings more than cryptanalysts'deductions. 许多年纪比较大的军官往往相信特务的发现，而不怎么相信密码分析员的推断。
• You know how you rush at things,jump to conclusions without proper deductions. 你知道你处理问题是多么仓促，毫无合适的演绎就仓促下结论。

249 ascertained   

v.弄清，确定，查明( ascertain的过去式和过去分词 )

参考例句：

• The previously unidentified objects have now been definitely ascertained as being satellites. 原来所说的不明飞行物现在已证实是卫星。 来自《简明英汉词典》
• I ascertained that she was dead. 我断定她已经死了。 来自《简明英汉词典》

250 cavil   

v.挑毛病，吹毛求疵

参考例句：

• A carper will cavil at anything.爱挑剔的人对什么都挑剔。
• Even he could find nothing to cavil about.连他都挑不出什么毛病来。

251 sloop   

n.单桅帆船

参考例句：

• They heeled the sloop well over,skimming it along to windward.他们使单桅小船倾斜适当，让它顶着风向前滑去。
• While a sloop always has two sails,a cat-rigged boat generally has only one.一艘单桅帆船总是有两面帆，但一艘单桅艇通常只有一面帆。

252 protagonist   

n.(思想观念的)倡导者；主角，主人公

参考例句：

• The protagonist reforms in the end and avoids his proper punishment.戏剧主角最后改过自新并避免了他应受的惩罚。
• He is the model for the protagonist in the play.剧本中的主人公就是以他为模特儿创作的！

253 sloops   

n.单桅纵帆船( sloop的名词复数 )

参考例句：

254 emulation   

n.竞争；仿效

参考例句：

• The young man worked hard in emulation of his famous father.这位年轻人努力工作，要迎头赶上他出名的父亲。
• His spirit of assiduous study is worthy of emulation.他刻苦钻研的精神，值得效法。

255 lashed   

adj.具睫毛的v.鞭打( lash的过去式和过去分词 )；煽动；紧系；怒斥

参考例句：

• The rain lashed at the windows. 雨点猛烈地打在窗户上。
• The cleverly designed speech lashed the audience into a frenzy. 这篇精心设计的演说煽动听众使他们发狂。 来自《简明英汉词典》

256 versus   

prep.以…为对手，对；与…相比之下

参考例句：

• The big match tonight is England versus Spain.今晚的大赛是英格兰对西班牙。
• The most exciting game was Harvard versus Yale.最富紧张刺激的球赛是哈佛队对耶鲁队。

257 bruited   

v.传播（传说或谣言）( bruit的过去式和过去分词 )

参考例句：

• This rumour has been bruited about for years. 这个谣言已传播多年了。
• The news was bruited through the town. 消息已传遍全城。 来自辞典例句

258 patriots   

爱国者，爱国主义者( patriot的名词复数 )

参考例句：

• Abraham Lincoln was a fine type of the American patriots. 亚伯拉罕·林肯是美国爱国者的优秀典型。
• These patriots would fight to death before they surrendered. 这些爱国者宁愿战斗到死，也不愿投降。

259 advent   

n.(重要事件等的)到来，来临

参考例句：

• Swallows come by groups at the advent of spring. 春天来临时燕子成群飞来。
• The advent of the Euro will redefine Europe.欧元的出现将重新定义欧洲。

260 regain   

vt.重新获得，收复，恢复

参考例句：

• He is making a bid to regain his World No.1 ranking.他正为重登世界排名第一位而努力。
• The government is desperate to regain credibility with the public.政府急于重新获取公众的信任。

261 emulate   

v.努力赶上或超越，与…竞争；效仿

参考例句：

• You must work hard to emulate your sister.你必须努力工作，赶上你姐姐。
• You must look at the film and try to emulate his behavior.你们必须观看这部电影，并尽力模仿他的动作。

262 redoubtable   

adj.可敬的；可怕的

参考例句：

• He is a redoubtable fighter.他是一位可敬的战士。
• Whose only defense is their will and redoubtable spirit.他们唯一的国防是他们的意志和可怕的精神。

263 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
• This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。

264 deceptions   

欺骗( deception的名词复数 )； 骗术，诡计

参考例句：

• Nobody saw through Mary's deceptions. 无人看透玛丽的诡计。
• There was for him only one trustworthy road through deceptions and mirages. 对他来说只有一条可靠的路能避开幻想和错觉。

265 hereditary   

adj.遗传的，遗传性的，可继承的，世袭的

参考例句：

• The Queen of England is a hereditary ruler.英国女王是世袭的统治者。
• In men,hair loss is hereditary.男性脱发属于遗传。

266 solely   

adv.仅仅，唯一地

参考例句：

• Success should not be measured solely by educational achievement.成功与否不应只用学业成绩来衡量。
• The town depends almost solely on the tourist trade.这座城市几乎完全靠旅游业维持。

267 arrogant   

adj.傲慢的，自大的

参考例句：

• You've got to get rid of your arrogant ways.你这骄傲劲儿得好好改改。
• People are waking up that he is arrogant.人们开始认识到他很傲慢。

268 eulogy   

n.颂词；颂扬

参考例句：

• He needs no eulogy from me or from any other man. 他不需要我或者任何一个人来称颂。
• Mr.Garth gave a long eulogy about their achievements in the research.加思先生对他们的研究成果大大地颂扬了一番。

269 outlay   

n.费用，经费，支出；v.花费

参考例句：

• There was very little outlay on new machinery.添置新机器的开支微乎其微。
• The outlay seems to bear no relation to the object aimed at.这费用似乎和预期目的完全不相称。

270 conversion   

n.转化，转换，转变

参考例句：

• He underwent quite a conversion.他彻底变了。
• Waste conversion is a part of the production process.废物处理是生产过程的一个组成部分。

271 conversions   

变换( conversion的名词复数 )； （宗教、信仰等）彻底改变； （尤指为居住而）改建的房屋； 橄榄球（触地得分后再把球射中球门的）附加得分

参考例句：

• He kicked a penalty goal and two conversions, ie in Rugby football. 他一次罚球得分，两次触地后射门得分（在橄榄球赛中）。
• Few of the intermediates or enzymes involved in these conversions have been isolated from higher plants. 在这些转变中包含的少数中间产物或酶已经从高等植物中分离出来。

272 undoubtedly   

adv.确实地，无疑地

参考例句：

• It is undoubtedly she who has said that.这话明明是她说的。
• He is undoubtedly the pride of China.毫无疑问他是中国的骄傲。

273 circuitous   

adj.迂回的路的，迂曲的，绕行的

参考例句：

• They took a circuitous route to avoid reporters.他们绕道避开了记者。
• The explanation was circuitous and puzzling.这个解释很迂曲，让人困惑不解。

274 augment   

vt.(使)增大，增加，增长，扩张

参考例句：

• They hit upon another idea to augment their income.他们又想出一个增加收入的办法。
• The government's first concern was to augment the army and auxiliary forces.政府首先关心的是增强军队和辅助的力量。

275 extremities   

n.端点( extremity的名词复数 )；尽头；手和足；极窘迫的境地

参考例句：

• She was most noticeable, I thought, in respect of her extremities. 我觉得她那副穷极可怜的样子实在太惹人注目。 来自辞典例句
• Winters may be quite cool at the northwestern extremities. 西北边区的冬天也可能会相当凉。 来自辞典例句

276 retarding   

使减速( retard的现在分词 )； 妨碍； 阻止； 推迟

参考例句：

• There may be a need for retarding growth chemically to keep trees within bounds. 可能需要用化学剂抑制生长，使树冠保持在一定的范围内。
• In some instances, an aversion to debt is retarding growth. 在某些情况下，对债务的反感正阻碍经济增长。

277 surmised   

v.臆测，推断( surmise的过去式和过去分词 )；揣测；猜想

参考例句：

• From the looks on their faces, I surmised that they had had an argument. 看他们的脸色，我猜想他们之间发生了争执。
• From his letter I surmised that he was unhappy. 我从他的信中推测他并不快乐。 来自《简明英汉词典》

278 inefficiency   

n.无效率，无能；无效率事例

参考例句：

• Conflict between management and workers makes for inefficiency in the workplace. 资方与工人之间的冲突使得工厂生产效率很低。 来自《简明英汉词典》
• This type of inefficiency arises because workers and management are ill-equipped. 出现此种低效率是因为工人与管理层都能力不足。 来自《简明英汉词典》

279 dwarf   

n.矮子，侏儒，矮小的动植物；vt.使…矮小

参考例句：

• The dwarf's long arms were not proportional to his height.那侏儒的长臂与他的身高不成比例。
• The dwarf shrugged his shoulders and shook his head. 矮子耸耸肩膀，摇摇头。

280 convened   

召开( convene的过去式 )； 召集； （为正式会议而）聚集； 集合

参考例句：

• The chairman convened the committee to put the issue to a vote. 主席召集委员们开会对这个问题进行表决。
• The governor convened his troops to put down the revolt. 总督召集他的部队去镇压叛乱。

281 sifting   

n.筛，过滤v.筛( sift的现在分词 )；筛滤；细查；详审

参考例句：

• He lay on the beach, sifting the sand through his fingers. 他躺在沙滩上用手筛砂子玩。 来自《简明英汉词典》
• I was sifting the cinders when she came in. 她进来时，我正在筛煤渣。 来自辞典例句

282 frigates   

n.快速军舰( frigate的名词复数 )

参考例句：

• Frigates are a vital part of any balanced sea-going fleet. 护卫舰是任何一个配置均衡的远洋舰队所必需的。 来自互联网
• These ships are based on the Chinese Jiangwei II class frigates. 这些战舰是基于中国的江卫II型护卫舰。 来自互联网

283 despatch   

n./v.(dispatch)派遣；发送；n.急件；新闻报道

参考例句：

• The despatch of the task force is purely a contingency measure.派出特遣部队纯粹是应急之举。
• He rushed the despatch through to headquarters.他把急件赶送到总部。

284 aggregate   

adj.总计的，集合的；n.总数；v.合计；集合

参考例句：

• The football team had a low goal aggregate last season.这支足球队上个赛季的进球总数很少。
• The money collected will aggregate a thousand dollars.进帐总额将达一千美元。

285 apprehension   

n.理解，领悟；逮捕，拘捕；忧虑

参考例句：

• There were still areas of doubt and her apprehension grew.有些地方仍然存疑，于是她越来越担心。
• She is a girl of weak apprehension.她是一个理解力很差的女孩。

286 hostility   

n.敌对，敌意；抵制［pl.］交战，战争

参考例句：

• There is open hostility between the two leaders.两位领导人表现出公开的敌意。
• His hostility to your plan is well known.他对你的计划所持的敌意是众所周知的。

287 skilful   

(=skillful)adj.灵巧的，熟练的

参考例句：

• The more you practise,the more skilful you'll become.练习的次数越多，熟练的程度越高。
• He's not very skilful with his chopsticks.他用筷子不大熟练。

288 lexicon   

n.字典，专门词汇

参考例句：

• Chocolate equals sin in most people's lexicon.巧克力在大多数人的字典里等同于罪恶。
• Silent earthquakes are only just beginning to enter the public lexicon.无声地震才刚开始要成为众所周知的语汇。

289 bias   

n.偏见，偏心，偏袒；vt.使有偏见

参考例句：

• They are accusing the teacher of political bias in his marking.他们在指控那名教师打分数有政治偏见。
• He had a bias toward the plan.他对这项计划有偏见。

290 contentions   

n.竞争( contention的名词复数 )；争夺；争论；论点

参考例句：

• Direct tests on individual particles do not support these contentions. 对单个粒子所作的直接试验并不支持这些论点。 来自辞典例句
• His contentions cannot be laughed out of court. 对他的争辩不能一笑置之。 来自辞典例句

291 professed   

公开声称的，伪称的，已立誓信教的

参考例句：

• These, at least, were their professed reasons for pulling out of the deal. 至少这些是他们自称退出这宗交易的理由。
• Her manner professed a gaiety that she did not feel. 她的神态显出一种她并未实际感受到的快乐。

292 squandered   

v.（指钱，财产等）浪费，乱花( squander的过去式和过去分词 )

参考例句：

• He squandered all his money on gambling. 他把自己所有的钱都糟蹋在赌博上了。
• She felt as indignant as if her own money had been squandered. 她心里十分生气，好像是她自己的钱给浪费掉了似的。 来自飘（部分）

293 exertions   

n.努力( exertion的名词复数 )；费力；（能力、权力等的）运用；行使

参考例句：

• As long as they lived, exertions would not be necessary to her. 只要他们活着，是不需要她吃苦的。 来自辞典例句
• She failed to unlock the safe in spite of all her exertions. 她虽然费尽力气，仍未能将那保险箱的锁打开。 来自辞典例句

294 galling   

adj.难堪的,使烦恼的,使焦躁的

参考例句：

• It was galling to have to apologize to a man she hated. 令人恼火的是得向她憎恶的男人道歉。
• The insolence in the fellow's eye was galling. 这家伙的傲慢目光令人恼怒。 来自英汉文学 - 嘉莉妹妹

295 thoroughly   

adv.完全地，彻底地，十足地

参考例句：

• The soil must be thoroughly turned over before planting.一定要先把土地深翻一遍再下种。
• The soldiers have been thoroughly instructed in the care of their weapons.士兵们都系统地接受过保护武器的训练。

296 hesitation   

n.犹豫，踌躇

参考例句：

• After a long hesitation, he told the truth at last.踌躇了半天，他终于直说了。
• There was a certain hesitation in her manner.她的态度有些犹豫不决。

297 vexed   

adj.争论不休的；（指问题等）棘手的；争论不休的问题；烦恼的v.使烦恼( vex的过去式和过去分词 )；使苦恼；使生气；详细讨论

参考例句：

• The conference spent days discussing the vexed question of border controls. 会议花了几天的时间讨论边境关卡这个难题。
• He was vexed at his failure. 他因失败而懊恼。 来自《现代汉英综合大词典》

298 disinterestedly   

参考例句：

• Few people behave disinterestedly in life. 生活中很少有人能表现得廉洁无私。 来自辞典例句
• He decided the case disinterestedly. 他公正地判决了那个案件。 来自互联网