Up to the close of the eighteenth century, the means of house and street illumination were of two generic8 kinds—grease and oil; but then came a swift and revolutionary change in the adoption9 of gas. The ideas and methods of Murdoch and Lebon soon took definite shape, and "coal smoke" was piped from its place of origin to distant points of consumption. As early as 1804, the first company ever organized for gas lighting was formed in London, one side of Pall10 Mall being lit up by the enthusiastic pioneer, Winsor, in 1807. Equal activity was shown in America, and Baltimore began the practice of gas lighting in 1816. It is true that there were explosions, and distinguished11 men like Davy and Watt12 opined that the illuminant was too dangerous; but the "spirit of coal" had demonstrated its usefulness convincingly, and a commercial development began, which, for extent and rapidity, was not inferior to that marking the concurrent13 adoption of steam in industry and transportation.
Meantime the wax candle and the Argand oil lamp held their own bravely. The whaling fleets, long after gas came into use, were one of the greatest sources of our national wealth. To New Bedford, Massachusetts, alone, some three or four hundred ships brought their whale and sperm15 oil, spermaceti, and whalebone; and at one time that port was accounted the richest city in the United States in proportion to its population. The ship-owners and refiners of that whaling metropolis16 were slow to believe that their monopoly could ever be threatened by newer sources of illumination; but gas had become available in the cities, and coal-oil and petroleum17 were now added to the list of illuminating18 materials. The American whaling fleet, which at the time of Edison's birth mustered19 over seven hundred sail, had dwindled20 probably to a bare tenth when he took up the problem of illumination; and the competition of oil from the ground with oil from the sea, and with coal-gas, had made the artificial production of light cheaper than ever before, when up to the middle of the century it had remained one of the heaviest items of domestic expense. Moreover, just about the time that Edison took up incandescent21 lighting, water-gas was being introduced on a large scale as a commercial illuminant that could be produced at a much lower cost than coal-gas.
Throughout the first half of the nineteenth century the search for a practical electric light was almost wholly in the direction of employing methods analogous22 to those already familiar; in other words, obtaining the illumination from the actual consumption of the light-giving material. In the third quarter of the century these methods were brought to practicality, but all may be referred back to the brilliant demonstrations24 of Sir Humphry Davy at the Royal Institution, circa 1809-10, when, with the current from a battery of two thousand cells, he produced an intense voltaic arc between the points of consuming sticks of charcoal25. For more than thirty years the arc light remained an expensive laboratory experiment; but the coming of the dynamo placed that illuminant on a commercial basis. The mere28 fact that electrical energy from the least expensive chemical battery using up zinc29 and acids costs twenty times as much as that from a dynamo—driven by steam-engine—is in itself enough to explain why so many of the electric arts lingered in embryo30 after their fundamental principles had been discovered. Here is seen also further proof of the great truth that one invention often waits for another.
From 1850 onward31 the improvements in both the arc lamp and the dynamo were rapid; and under the superintendence of the great Faraday, in 1858, protecting beams of intense electric light from the voltaic arc were shed over the waters of the Straits of Dover from the beacons32 of South Foreland and Dungeness. By 1878 the arc-lighting industry had sprung into existence in so promising33 a manner as to engender34 an extraordinary fever and furor35 of speculation36. At the Philadelphia Centennial Exposition of 1876, Wallace-Farmer dynamos built at Ansonia, Connecticut, were shown, with the current from which arc lamps were there put in actual service. A year or two later the work of Charles F. Brush and Edward Weston laid the deep foundation of modern arc lighting in America, securing as well substantial recognition abroad.
Thus the new era had been ushered37 in, but it was based altogether on the consumption of some material—carbon—in a lamp open to the air. Every lamp the world had ever known did this, in one way or another. Edison himself began at that point, and his note-books show that he made various experiments with this type of lamp at a very early stage. Indeed, his experiments had led him so far as to anticipate in 1875 what are now known as "flaming arcs," the exceedingly bright and generally orange or rose-colored lights which have been introduced within the last few years, and are now so frequently seen in streets and public places. While the arcs with plain carbons are bluish-white, those with carbons containing calcium38 fluoride have a notable golden glow.
He was convinced, however, that the greatest field of lighting lay in the illumination of houses and other comparatively enclosed areas, to replace the ordinary gas light, rather than in the illumination of streets and other outdoor places by lights of great volume and brilliancy. Dismissing from his mind quickly the commercial impossibility of using arc lights for general indoor illumination, he arrived at the conclusion that an electric lamp giving light by incandescence39 was the solution of the problem.
Edison was familiar with the numerous but impracticable and commercially unsuccessful efforts that had been previously40 made by other inventors and investigators41 to produce electric light by incandescence, and at the time that he began his experiments, in 1877, almost the whole scientific world had pronounced such an idea as impossible of fulfilment. The leading electricians, physicists43, and experts of the period had been studying the subject for more than a quarter of a century, and with but one known exception had proven mathematically and by close reasoning that the "Subdivision of the Electric Light," as it was then termed, was practically beyond attainment44. Opinions of this nature have ever been but a stimulus45 to Edison when he has given deep thought to a subject, and has become impressed with strong convictions of possibility, and in this particular case he was satisfied that the subdivision of the electric light—or, more correctly, the subdivision of the electric current—was not only possible but entirely46 practicable.
It will have been perceived from the foregoing chapters that from the time of boyhood, when he first began to rub against the world, his commercial instincts were alert and predominated in almost all of the enterprises that he set in motion. This characteristic trait had grown stronger as he matured, having received, as it did, fresh impetus47 and strength from his one lapse48 in the case of his first patented invention, the vote-recorder. The lesson he then learned was to devote his inventive faculties49 only to things for which there was a real, genuine demand, and that would subserve the actual necessities of humanity; and it was probably a fortunate circumstance that this lesson was learned at the outset of his career as an inventor. He has never assumed to be a philosopher or "pure scientist."
In order that the reader may grasp an adequate idea of the magnitude and importance of Edison's invention of the incandescent lamp, it will be necessary to review briefly50 the "state of the art" at the time he began his experiments on that line. After the invention of the voltaic battery, early in the last century, experiments were made which determined51 that heat could be produced by the passage of the electric current through wires of platinum53 and other metals, and through pieces of carbon, as noted54 already, and it was, of course, also observed that if sufficient current were passed through these conductors they could be brought from the lower stage of redness up to the brilliant white heat of incandescence. As early as 1845 the results of these experiments were taken advantage of when Starr, a talented American who died at the early age of twenty-five, suggested, in his English patent of that year, two forms of small incandescent electric lamps, one having a burner made from platinum foil placed under a glass cover without excluding the air; and the other composed of a thin plate or pencil of carbon enclosed in a Torricellian vacuum. These suggestions of young Starr were followed by many other experimenters, whose improvements consisted principally in devices to increase the compactness and portability of the lamp, in the sealing of the lamp chamber56 to prevent the admission of air, and in means for renewing the carbon burner when it had been consumed. Thus Roberts, in 1852, proposed to cement the neck of the glass globe into a metallic57 cup, and to provide it with a tube or stop-cock for exhaustion58 by means of a hand-pump. Lodyguine, Konn, Kosloff, and Khotinsky, between 1872 and 1877, proposed various ingenious devices for perfecting the joint59 between the metal base and the glass globe, and also provided their lamps with several short carbon pencils, which were automatically brought into circuit successively as the pencils were consumed. In 1876 or 1877, Bouliguine proposed the employment of a long carbon pencil, a short section only of which was in circuit at any one time and formed the burner, the lamp being provided with a mechanism60 for automatically pushing other sections of the pencil into position between the contacts to renew the burner. Sawyer and Man proposed, in 1878, to make the bottom plate of glass instead of metal, and provided ingenious arrangements for charging the lamp chamber with an atmosphere of pure nitrogen gas which does not support combustion61.
These lamps and many others of similar character, ingenious as they were, failed to become of any commercial value, due, among other things, to the brief life of the carbon burner. Even under the best conditions it was found that the carbon members were subject to a rapid disintegration62 or evaporation63, which experimenters assumed was due to the disrupting action of the electric current; and hence the conclusion that carbon contained in itself the elements of its own destruction, and was not a suitable material for the burner of an incandescent lamp. On the other hand, platinum, although found to be the best of all materials for the purpose, aside from its great expense, and not combining with oxygen at high temperatures as does carbon, required to be brought so near the melting-point in order to give light, that a very slight increase in the temperature resulted in its destruction. It was assumed that the difficulty lay in the material of the burner itself, and not in its environment.
It was not realized up to such a comparatively recent date as 1879 that the solution of the great problem of subdivision of the electric current would not, however, be found merely in the production of a durable64 incandescent electric lamp—even if any of the lamps above referred to had fulfilled that requirement. The other principal features necessary to subdivide65 the electric current successfully were: the burning of an indefinite number of lights on the same circuit; each light to give a useful and economical degree of illumination; and each light to be independent of all the others in regard to its operation and extinguishment.
The opinions of scientific men of the period on the subject are well represented by the two following extracts—the first, from a lecture at the Royal United Service Institution, about February, 1879, by Mr. (Sir) W. H. Preece, one of the most eminent67 electricians in England, who, after discussing the question mathematically, said: "Hence the sub-division of the light is an absolute ignis fatuus." The other extract is from a book written by Paget Higgs, LL.D., D.Sc., published in London in 1879, in which he says: "Much nonsense has been talked in relation to this subject. Some inventors have claimed the power to 'indefinitely divide' the electric current, not knowing or forgetting that such a statement is incompatible68 with the well-proven law of conservation of energy."
"Some inventors," in the last sentence just quoted, probably—indeed, we think undoubtedly69—refers to Edison, whose earlier work in electric lighting (1878) had been announced in this country and abroad, and who had then stated boldly his conviction of the practicability of the subdivision of the electrical current. The above extracts are good illustrations, however, of scientific opinions up to the end of 1879, when Mr. Edison's epoch-making invention rendered them entirely untenable. The eminent scientist, John Tyndall, while not sharing these precise views, at least as late as January 17, 1879, delivered a lecture before the Royal Institution on "The Electric Light," when, after pointing out the development of the art up to Edison's work, and showing the apparent hopelessness of the problem, he said: "Knowing something of the intricacy of the practical problem, I should certainly prefer seeing it in Edison's hands to having it in mine."
The reader may have deemed this sketch70 of the state of the art to be a considerable digression; but it is certainly due to the subject to present the facts in such a manner as to show that this great invention was neither the result of improving some process or device that was known or existing at the time, nor due to any unforeseen lucky chance, nor the accidental result of other experiments. On the contrary, it was the legitimate71 outcome of a series of exhaustive experiments founded upon logical and original reasoning in a mind that had the courage and hardihood to set at naught72 the confirmed opinions of the world, voiced by those generally acknowledged to be the best exponents73 of the art—experiments carried on amid a storm of jeers74 and derision, almost as contemptuous as if the search were for the discovery of perpetual motion. In this we see the man foreshadowed by the boy who, when he obtained his books on chemistry or physics, did not accept any statement of fact or experiment therein, but worked out every one of them himself to ascertain75 whether or not they were true.
Although this brings the reader up to the year 1879, one must turn back two years and accompany Edison in his first attack on the electric-light problem. In 1877 he sold his telephone invention (the carbon transmitter) to the Western union Telegraph Company, which had previously come into possession also of his quadruplex inventions, as already related. He was still busily engaged on the telephone, on acoustic76 electrical transmission, sextuplex telegraphs, duplex telegraphs, miscellaneous carbon articles, and other inventions of a minor77 nature. During the whole of the previous year and until late in the summer of 1877, he had been working with characteristic energy and enthusiasm on the telephone; and, in developing this invention to a successful issue, had preferred the use of carbon and had employed it in numerous forms, especially in the form of carbonized paper.
Eighteen hundred and seventy-seven in Edison's laboratory was a veritable carbon year, for it was carbon in some shape or form for interpolation in electric circuits of various kinds that occupied the thoughts of the whole force from morning to night. It is not surprising, therefore, that in September of that year, when Edison turned his thoughts actively79 toward electric lighting by incandescence, his early experiments should be in the line of carbon as an illuminant. His originality80 of method was displayed at the very outset, for one of the first experiments was the bringing to incandescence of a strip of carbon in the open air to ascertain merely how much current was required. This conductor was a strip of carbonized paper about an inch long, one-sixteenth of an inch broad, and six or seven one-thousandths of an inch thick, the ends of which were secured to clamps that formed the poles of a battery. The carbon was lighted up to incandescence, and, of course, oxidized and disintegrated81 immediately. Within a few days this was followed by experiments with the same kind of carbon, but in vacuo by means of a hand-worked air-pump. This time the carbon strip burned at incandescence for about eight minutes. Various expedients84 to prevent oxidization were tried, such, for instance, as coating the carbon with powdered glass, which in melting would protect the carbon from the atmosphere, but without successful results.
Edison was inclined to concur14 in the prevailing85 opinion as to the easy destructibility of carbon, but, without actually settling the point in his mind, he laid aside temporarily this line of experiment and entered a new field. He had made previously some trials of platinum wire as an incandescent burner for a lamp, but left it for a time in favor of carbon. He now turned to the use of almost infusible metals—such as boron, ruthenium, chromium, etc.—as separators or tiny bridges between two carbon points, the current acting86 so as to bring these separators to a high degree of incandescence, at which point they would emit a brilliant light. He also placed some of these refractory87 metals directly in the circuit, bringing them to incandescence, and used silicon88 in powdered form in glass tubes placed in the electric circuit. His notes include the use of powdered silicon mixed with lime or other very infusible non-conductors or semi-conductors. Edison's conclusions on these substances were that, while in some respects they were within the bounds of possibility for the subdivision of the electric current, they did not reach the ideal that he had in mind for commercial results.
Edison's systematized attacks on the problem were two in number, the first of which we have just related, which began in September, 1877, and continued until about January, 1878. Contemporaneously, he and his force of men were very busily engaged day and night on other important enterprises and inventions. Among the latter, the phonograph may be specially78 mentioned, as it was invented in the late fall of 1877. From that time until July, 1878, his time and attention day and night were almost completely absorbed by the excitement caused by the invention and exhibition of the machine. In July, feeling entitled to a brief vacation after several years of continuous labor26, Edison went with the expedition to Wyoming to observe an eclipse of the sun, and incidentally to test his tasimeter, a delicate instrument devised by him for measuring heat transmitted through immense distances of space. His trip has been already described. He was absent about two months. Coming home rested and refreshed, Mr. Edison says: "After my return from the trip to observe the eclipse of the sun, I went with Professor Barker, Professor of Physics in the University of Pennsylvania, and Doctor Chandler, Professor of Chemistry in Columbia College, to see Mr. Wallace, a large manufacturer of brass89 in Ansonia, Connecticut. Wallace at this time was experimenting on series arc lighting. Just at that time I wanted to take up something new, and Professor Barker suggested that I go to work and see if I could subdivide the electric light so it could be got in small units like gas. This was not a new suggestion, because I had made a number of experiments on electric lighting a year before this. They had been laid aside for the phonograph. I determined to take up the search again and continue it. On my return home I started my usual course of collecting every kind of data about gas; bought all the transactions of the gas-engineering societies, etc., all the back volumes of gas journals, etc. Having obtained all the data, and investigated gas-jet distribution in New York by actual observations, I made up my mind that the problem of the subdivision of the electric current could be solved and made commercial." About the end of August, 1878, he began his second organized attack on the subdivision of the current, which was steadily90 maintained until he achieved signal victory a year and two months later.
The date of this interesting visit to Ansonia is fixed91 by an inscription92 made by Edison on a glass goblet93 which he used. The legend in diamond scratches runs: "Thomas A. Edison, September 8, 1878, made under the electric light." Other members of the party left similar memorials, which under the circumstances have come to be greatly prized. A number of experiments were witnessed in arc lighting, and Edison secured a small Wallace-Farmer dynamo for his own work, as well as a set of Wallace arc lamps for lighting the Menlo Park laboratory. Before leaving Ansonia, Edison remarked, significantly: "Wallace, I believe I can beat you making electric lights. I don't think you are working in the right direction." Another date which shows how promptly94 the work was resumed is October 14, 1878, when Edison filed an application for his first lighting patent: "Improvement in Electric Lights." In after years, discussing the work of Wallace, who was not only a great pioneer electrical manufacturer, but one of the founders95 of the wire-drawing and brass-working industry, Edison said: "Wallace was one of the earliest pioneers in electrical matters in this country. He has done a great deal of good work, for which others have received the credit; and the work which he did in the early days of electric lighting others have benefited by largely, and he has been crowded to one side and forgotten." Associated in all this work with Wallace at Ansonia was Prof. Moses G. Farmer, famous for the introduction of the fire-alarm system; as the discoverer of the self-exciting principle of the modern dynamo; as a pioneer experimenter in the electric-railway field; as a telegraph engineer, and as a lecturer on mines and explosives to naval96 classes at Newport. During 1858, Farmer, who, like Edison, was a ceaseless investigator42, had made a series of studies upon the production of light by electricity, and had even invented an automatic regulator by which a number of platinum lamps in multiple arc could be kept at uniform voltage for any length of time. In July, 1859, he lit up one of the rooms of his house at Salem, Massachusetts, every evening with such lamps, using in them small pieces of platinum and iridium wire, which were made to incandesce by means of current from primary batteries. Farmer was not one of the party that memorable97 day in September, but his work was known through his intimate connection with Wallace, and there is no doubt that reference was made to it. Such work had not led very far, the "lamps" were hopelessly short-lived, and everything was obviously experimental; but it was all helpful and suggestive to one whose open mind refused no hint from any quarter.
At the commencement of his new attempts, Edison returned to his experiments with carbon as an incandescent burner for a lamp, and made a very large number of trials, all in vacuo. Not only were the ordinary strip paper carbons tried again, but tissue-paper coated with tar55 and lampblack was rolled into thin sticks, like knitting-needles, carbonized and raised to incandescence in vacuo. Edison also tried hard carbon, wood carbons, and almost every conceivable variety of paper carbon in like manner. With the best vacuum that he could then get by means of the ordinary air-pump, the carbons would last, at the most, only from ten to fifteen minutes in a state of incandescence. Such results were evidently not of commercial value.
Edison then turned his attention in other directions. In his earliest consideration of the problem of subdividing98 the electric current, he had decided99 that the only possible solution lay in the employment of a lamp whose incandescing body should have a high resistance combined with a small radiating surface, and be capable of being used in what is called "multiple arc," so that each unit, or lamp, could be turned on or off without interfering100 with any other unit or lamp. No other arrangement could possibly be considered as commercially practicable.
The full significance of the three last preceding sentences will not be obvious to laymen101, as undoubtedly many of the readers of this book may be; and now being on the threshold of the series of Edison's experiments that led up to the basic invention, we interpolate a brief explanation, in order that the reader may comprehend the logical reasoning and work that in this case produced such far-reaching results.
If we consider a simple circuit in which a current is flowing, and include in the circuit a carbon horseshoe-like conductor which it is desired to bring to incandescence by the heat generated by the current passing through it, it is first evident that the resistance offered to the current by the wires themselves must be less than that offered by the burner, because, otherwise current would be wasted as heat in the conducting wires. At the very foundation of the electric-lighting art is the essentially102 commercial consideration that one cannot spend very much for conductors, and Edison determined that, in order to use wires of a practicable size, the voltage of the current (i.e., its pressure or the characteristic that overcomes resistance to its flow) should be one hundred and ten volts103, which since its adoption has been the standard. To use a lower voltage or pressure, while making the solution of the lighting problem a simple one as we shall see, would make it necessary to increase the size of the conducting wires to a prohibitive extent. To increase the voltage or pressure materially, while permitting some saving in the cost of conductors, would enormously increase the difficulties of making a sufficiently104 high resistance conductor to secure light by incandescence. This apparently105 remote consideration —weight of copper106 used—was really the commercial key to the problem, just as the incandescent burner was the scientific key to that problem. Before Edison's invention incandescent lamps had been suggested as a possibility, but they were provided with carbon rods or strips of relatively107 low resistance, and to bring these to incandescence required a current of low pressure, because a current of high voltage would pass through them so readily as not to generate heat; and to carry a current of low pressure through wires without loss would require wires of enormous size. [8] Having a current of relatively high pressure to contend with, it was necessary to provide a carbon burner which, as compared with what had previously been suggested, should have a very great resistance. Carbon as a material, determined after patient search, apparently offered the greatest hope, but even with this substance the necessary high resistance could be obtained only by making the burner of extremely small cross-section, thereby108 also reducing its radiating surface. Therefore, the crucial point was the production of a hair-like carbon filament109, with a relatively great resistance and small radiating surface, capable of withstanding mechanical shock, and susceptible110 of being maintained at a temperature of over two thousand degrees for a thousand hours or more before breaking. And this filamentary111 conductor required to be supported in a vacuum chamber so perfectly112 formed and constructed that during all those hours, and subjected as it is to varying temperatures, not a particle of air should enter to disintegrate82 the filament. And not only so, but the lamp after its design must not be a mere laboratory possibility, but a practical commercial article capable of being manufactured at low cost and in large quantities. A statement of what had to be done in those days of actual as well as scientific electrical darkness is quite sufficient to explain Tyndall's attitude of mind in preferring that the problem should be in Edison's hands rather than in his own. To say that the solution of the problem lay merely in reducing the size of the carbon burner to a mere hair, is to state a half-truth only; but who, we ask, would have had the temerity113 even to suggest that such an attenuated114 body could be maintained at a white heat, without disintegration, for a thousand hours? The solution consisted not only in that, but in the enormous mass of patiently worked-out details—the manufacture of the filaments115, their uniform carbonization, making the globes, producing a perfect vacuum, and countless116 other factors, the omission117 of any one of which would probably have resulted eventually in failure.
[Footnote 8: As a practical illustration of these facts it
was calculated by Professor Barker, of the University of
Pennsylvania (after Edison had invented the incandescent
lamp), that if it should cost $100,000 for copper conductors
to supply current to Edison lamps in a given area, it would
cost about $200,000,000 for copper conductors for lighting
the same area by lamps of the earlier experimenters—such,
for instance, as the lamp invented by Konn in 1875. This
enormous difference would be accounted for by the fact that
Edison's lamp was one having a high resistance and
relatively small radiating surface, while Konn's lamp was
one having a very low resistance and large radiating
surface.]
Continuing the digression one step farther in order to explain the term "multiple arc," it may be stated that there are two principal systems of distributing electric current, one termed "series," and the other "multiple arc." The two are illustrated118, diagrammatically, side by side, the arrows indicating flow of current. The series system, it will be seen, presents one continuous path for the current. The current for the last lamp must pass through the first and all the intermediate lamps. Hence, if any one light goes out, the continuity of the path is broken, current cannot flow, and all the lamps are extinguished unless a loop or by-path is provided. It is quite obvious that such a system would be commercially impracticable where small units, similar to gas jets, were employed. On the other hand, in the multiple-arc system, current may be considered as flowing in two parallel conductors like the vertical119 sides of a ladder, the ends of which never come together. Each lamp is placed in a separate circuit across these two conductors, like a rung in the ladder, thus making a separate and independent path for the current in each case. Hence, if a lamp goes out, only that individual subdivision, or ladder step, is affected120; just that one particular path for the current is interrupted, but none of the other lamps is interfered121 with. They remain lighted, each one independent of the other. The reader will quite readily understand, therefore, that a multiple-arc system is the only one practically commercial where electric light is to be used in small units like those of gas or oil.
Such was the nature of the problem that confronted Edison at the outset. There was nothing in the whole world that in any way approximated a solution, although the most brilliant minds in the electrical art had been assiduously working on the subject for a quarter of a century preceding. As already seen, he came early to the conclusion that the only solution lay in the use of a lamp of high resistance and small radiating surface, and, with characteristic fervor122 and energy, he attacked the problem from this standpoint, having absolute faith in a successful outcome. The mere fact that even with the successful production of the electric lamp the assault on the complete problem of commercial lighting would hardly be begun did not deter52 him in the slightest. To one of Edison's enthusiastic self-confidence the long vista123 of difficulties ahead—we say it in all sincerity—must have been alluring124.
After having devoted125 several months to experimental trials of carbon, at the end of 1878, as already detailed126, he turned his attention to the platinum group of metals and began a series of experiments in which he used chiefly platinum wire and iridium wire, and alloys127 of refractory metals in the form of wire burners for incandescent lamps. These metals have very high fusing-points, and were found to last longer than the carbon strips previously used when heated up to incandescence by the electric current, although under such conditions as were then possible they were melted by excess of current after they had been lighted a comparatively short time, either in the open air or in such a vacuum as could be obtained by means of the ordinary air-pump.
Nevertheless, Edison continued along this line of experiment with unremitting vigor128, making improvement after improvement, until about April, 1879, he devised a means whereby platinum wire of a given length, which would melt in the open air when giving a light equal to four candles, would emit a light of twenty-five candle-power without fusion129. This was accomplished130 by introducing the platinum wire into an all-glass globe, completely sealed and highly exhausted131 of air, and passing a current through the platinum wire while the vacuum was being made. In this, which was a new and radical132 invention, we see the first step toward the modern incandescent lamp. The knowledge thus obtained that current passing through the platinum during exhaustion would drive out occluded133 gases (i.e., gases mechanically held in or upon the metal), and increase the infusibility of the platinum, led him to aim at securing greater perfection in the vacuum, on the theory that the higher the vacuum obtained, the higher would be the infusibility of the platinum burner. And this fact also was of the greatest importance in making successful the final use of carbon, because without the subjection of the carbon to the heating effect of current during the formation of the vacuum, the presence of occluded gases would have been a fatal obstacle.
Continuing these experiments with most fervent134 zeal135, taking no account of the passage of time, with an utter disregard for meals, and but scanty136 hours of sleep snatched reluctantly at odd periods of the day or night, Edison kept his laboratory going without cessation. A great variety of lamps was made of the platinum-iridium type, mostly with thermal137 devices to regulate the temperature of the burner and prevent its being melted by an excess of current. The study of apparatus138 for obtaining more perfect vacua was unceasingly carried on, for Edison realized that in this there lay a potent139 factor of ultimate success. About August he had obtained a pump that would produce a vacuum up to about the one-hundred-thousandth part of an atmosphere, and some time during the next month, or beginning of October, had obtained one that would produce a vacuum up to the one-millionth part of an atmosphere. It must be remembered that the conditions necessary for MAINTAINING this high vacuum were only made possible by his invention of the one-piece all-glass globe, in which all the joints140 were hermetically sealed during its manufacture into a lamp, whereby a high vacuum could be retained continuously for any length of time.
In obtaining this perfection of vacuum apparatus, Edison realized that he was approaching much nearer to a solution of the problem. In his experiments with the platinum-iridium lamps, he had been working all the time toward the proposition of high resistance and small radiating surface, until he had made a lamp having thirty feet of fine platinum wire wound upon a small bobbin of infusible material; but the desired economy, simplicity141, and durability142 were not obtained in this manner, although at all times the burner was maintained at a critically high temperature. After attaining143 a high degree of perfection with these lamps, he recognized their impracticable character, and his mind reverted144 to the opinion he had formed in his early experiments two years before—viz., that carbon had the requisite145 resistance to permit a very simple conductor to accomplish the object if it could be used in the form of a hair-like "filament," provided the filament itself could be made sufficiently homogeneous. As we have already seen, he could not use carbon successfully in his earlier experiments, for the strips of carbon he then employed, although they were much larger than "filaments," would not stand, but were consumed in a few minutes under the imperfect conditions then at his command.
Now, however, that he had found means for obtaining and maintaining high vacua, Edison immediately went back to carbon, which from the first he had conceived of as the ideal substance for a burner. His next step proved conclusively146 the correctness of his old deductions147. On October 21, 1879, after many patient trials, he carbonized a piece of cotton sewing-thread bent148 into a loop or horseshoe form, and had it sealed into a glass globe from which he exhausted the air until a vacuum up to one-millionth of an atmosphere was produced. This lamp, when put on the circuit, lighted up brightly to incandescence and maintained its integrity for over forty hours, and lo! the practical incandescent lamp was born. The impossible, so called, had been attained149; subdivision of the electric-light current was made practicable; the goal had been reached; and one of the greatest inventions of the century was completed. Up to this time Edison had spent over $40,000 in his electric-light experiments, but the results far more than justified150 the expenditure151, for with this lamp he made the discovery that the FILAMENT of carbon, under the conditions of high vacuum, was commercially stable and would stand high temperatures without the disintegration and oxidation that took place in all previous attempts that he knew of for making an incandescent burner out of carbon. Besides, this lamp possessed152 the characteristics of high resistance and small radiating surface, permitting economy in the outlay153 for conductors, and requiring only a small current for each unit of light—conditions that were absolutely necessary of fulfilment in order to accomplish commercially the subdivision of the electric-light current.
This slender, fragile, tenuous154 thread of brittle155 carbon, glowing steadily and continuously with a soft light agreeable to the eyes, was the tiny key that opened the door to a world revolutionized in its interior illumination. It was a triumphant156 vindication157 of Edison's reasoning powers, his clear perceptions, his insight into possibilities, and his inventive faculty158, all of which had already been productive of so many startling, practical, and epoch-making inventions. And now he had stepped over the threshold of a new art which has since become so world-wide in its application as to be an integral part of modern human experience. [9]
[Footnote 9: The following extract from Walker on Patents
(4th edition) will probably be of interest to the reader:
"Sec. 31a. A meritorious159 exception, to the rule of the last
section, is involved in the adjudicated validity of the
Edison incandescent-light patent. The carbon filament, which
constitutes the only new part of the combination of the
second claim of that patent, differs from the earlier carbon
burners of Sawyer and Man, only in having a diameter of one-
sixty-fourth of an inch or less, whereas the burners of
Sawyer and Man had a diameter of one-thirty-second of an
inch or more. But that reduction of one-half in diameter
increased the resistance of the burner FOURFOLD, and reduced
its radiating surface TWOFOLD, and thus increased eightfold,
its ratio of resistance to radiating surface. That eightfold
increase of proportion enabled the resistance of the
be increased eightfold, without any increase of percentage
of loss of energy in that conductor, or decrease of
percentage of development of heat in the burner; and thus
enabled the area of the cross-section of that conductor to
be reduced eightfold, and thus to be made with one-eighth of
the amount of copper or other metal, which would be required
if the reduction of diameter of the burner from one-thirty-
second to one-sixty-fourth of an inch had not been made. And
that great reduction in the size and cost of conductors,
involved also a great difference in the composition of the
electric energy employed in the system; that difference
consisting in generating the necessary amount of electrical
energy with comparatively high electromotive force, and
comparatively low current, instead of contrariwise. For this
reason, the use of carbon filaments, one-sixty-fourth of an
inch in diameter or less, instead of carbon burners one-
thirty-second of an inch in diameter or more, not only
worked an enormous economy in conductors, but also
according to a philosophy, which Edison was the first to
know, and which is stated in this paragraph in its simplest
form and aspect, and which lies at the foundation of the
incandescent electric lighting of the world."]
No sooner had the truth of this new principle been established than the work to establish it firmly and commercially was carried on more assiduously than ever. The next immediate83 step was a further investigation163 of the possibilities of improving the quality of the carbon filament. Edison had previously made a vast number of experiments with carbonized paper for various electrical purposes, with such good results that he once more turned to it and now made fine filament-like loops of this material which were put into other lamps. These proved even more successful (commercially considered) than the carbonized thread—so much so that after a number of such lamps had been made and put through severe tests, the manufacture of lamps from these paper carbons was begun and carried on continuously. This necessitated first the devising and making of a large number of special tools for cutting the carbon filaments and for making and putting together the various parts of the lamps. Meantime, great excitement had been caused in this country and in Europe by the announcement of Edison's success. In the Old World, scientists generally still declared the impossibility of subdividing the electric-light current, and in the public press Mr. Edison was denounced as a dreamer. Other names of a less complimentary164 nature were applied165 to him, even though his lamp were actually in use, and the principle of commercial incandescent lighting had been established.
Between October 21, 1879, and December 21, 1879, some hundreds of these paper-carbon lamps had been made and put into actual use, not only in the laboratory, but in the streets and several residences at Menlo Park, New Jersey166, causing great excitement and bringing many visitors from far and near. On the latter date a full-page article appeared in the New York Herald167 which so intensified168 the excited feeling that Mr. Edison deemed it advisable to make a public exhibition. On New Year's Eve, 1879, special trains were run to Menlo Park by the Pennsylvania Railroad, and over three thousand persons took advantage of the opportunity to go out there and witness this demonstration23 for themselves. In this great crowd were many public officials and men of prominence169 in all walks of life, who were enthusiastic in their praises.
In the mean time, the mind that conceived and made practical this invention could not rest content with anything less than perfection, so far as it could be realized. Edison was not satisfied with paper carbons. They were not fully66 up to the ideal that he had in mind. What he sought was a perfectly uniform and homogeneous carbon, one like the "One-Hoss Shay," that had no weak spots to break down at inopportune times. He began to carbonize everything in nature that he could lay hands on. In his laboratory note-books are innumerable jottings of the things that were carbonized and tried, such as tissue-paper, soft paper, all kinds of cardboards, drawing-paper of all grades, paper saturated170 with tar, all kinds of threads, fish-line, threads rubbed with tarred lampblack, fine threads plaited together in strands171, cotton soaked in boiling tar, lamp-wick, twine172, tar and lampblack mixed with a proportion of lime, vulcanized fibre, celluloid, boxwood, cocoanut hair and shell, spruce, hickory, baywood, cedar173 and maple174 shavings, rosewood, punk, cork175, bagging, flax, and a host of other things. He also extended his searches far into the realms of nature in the line of grasses, plants, canes177, and similar products, and in these experiments at that time and later he carbonized, made into lamps, and tested no fewer than six thousand different species of vegetable growths.
The reasons for such prodigious178 research are not apparent on the face of the subject, nor is this the occasion to enter into an explanation, as that alone would be sufficient to fill a fair-sized book. Suffice it to say that Edison's omnivorous179 reading, keen observation, power of assimilating facts and natural phenomena180, and skill in applying the knowledge thus attained to whatever was in hand, now came into full play in determining that the results he desired could only be obtained in certain directions.
At this time he was investigating everything with a microscope, and one day in the early part of 1880 he noticed upon a table in the laboratory an ordinary palm-leaf fan. He picked it up and, looking it over, observed that it had a binding181 rim27 made of bamboo, cut from the outer edge of the cane176; a very long strip. He examined this, and then gave it to one of his assistants, telling him to cut it up and get out of it all the filaments he could, carbonize them, put them into lamps, and try them. The results of this trial were exceedingly successful, far better than with anything else thus far used; indeed, so much so, that after further experiments and microscopic182 examinations Edison was convinced that he was now on the right track for making a thoroughly183 stable, commercial lamp; and shortly afterward184 he sent a man to Japan to procure185 further supplies of bamboo. The fascinating story of the bamboo hunt will be told later; but even this bamboo lamp was only one item of a complete system to be devised—a system that has since completely revolutionized the art of interior illumination.
Reference has been made in this chapter to the preliminary study that Edison brought to bear on the development of the gas art and industry. This study was so exhaustive that one can only compare it to the careful investigation made in advance by any competent war staff of the elements of strength and weakness, on both sides, in a possible campaign. A popular idea of Edison that dies hard, pictures a breezy, slap-dash, energetic inventor arriving at new results by luck and intuition, making boastful assertions and then winning out by mere chance. The native simplicity of the man, the absence of pose and ceremony, do much to strengthen this notion; but the real truth is that while gifted with unusual imagination, Edison's march to the goal of a new invention is positively186 humdrum187 and monotonous188 in its steady progress. No one ever saw Edison in a hurry; no one ever saw him lazy; and that which he did with slow, careful scrutiny189 six months ago, he will be doing with just as much calm deliberation of research six months hence—and six years hence if necessary. If, for instance, he were asked to find the most perfect pebble190 on the Atlantic shore of New Jersey, instead of hunting here, there, and everywhere for the desired object, we would no doubt find him patiently screening the entire beach, sifting191 out the most perfect stones and eventually, by gradual exclusion192, reaching the long-sought-for pebble; and the mere fact that in this search years might be taken, would not lessen193 his enthusiasm to the slightest extent.
In the "prospectus194 book" among the series of famous note-books, all the references and data apply to gas. The book is numbered 184, falls into the period now dealt with, and runs along casually195 with items spread out over two or three years. All these notes refer specifically to "Electricity vs. Gas as General Illuminants," and cover an astounding196 range of inquiry197 and comment. One of the very first notes tells the whole story: "Object, Edison to effect exact imitation of all done by gas, so as to replace lighting by gas by lighting by electricity. To improve the illumination to such an extent as to meet all requirements of natural, artificial, and commercial conditions." A large programme, but fully executed! The notes, it will be understood, are all in Edison's handwriting. They go on to observe that "a general system of distribution is the only possible means of economical illumination," and they dismiss isolated-plant lighting as in mills and factories as of so little importance to the public—"we shall leave the consideration of this out of this book." The shrewd prophecy is made that gas will be manufactured less for lighting, as the result of electrical competition, and more and more for heating, etc., thus enlarging its market and increasing its income. Comment is made on kerosene198 and its cost, and all kinds of general statistics are jotted199 down as desirable. Data are to be obtained on lamp and dynamo efficiency, and "Another review of the whole thing as worked out upon pure science principles by Rowland, Young, Trowbridge; also Rowland on the possibilities and probabilities of cheaper production by better manufacture—higher incandescence without decrease of life of lamps." Notes are also made on meters and motors. "It doesn't matter if electricity is used for light or for power"; while small motors, it is observed, can be used night or day, and small steam-engines are inconvenient200. Again the shrewd comment: "Generally poorest district for light, best for power, thus evening up whole city—the effect of this on investment."
It is pointed201 out that "Previous inventions failed—necessities for commercial success and accomplishment202 by Edison. Edison's great effort—not to make a large light or a blinding light, but a small light having the mildness of gas." Curves are then called for of iron and copper investment—also energy line—curves of candle-power and electromotive force; curves on motors; graphic203 representation of the consumption of gas January to December; tables and formulae; representations graphically204 of what one dollar will buy in different kinds of light; "table, weight of copper required different distance, 100-ohm lamp, 16 candles"; table with curves showing increased economy by larger engine, higher power, etc. There is not much that is dilettante205 about all this. Note is made of an article in April, 1879, putting the total amount of gas investment in the whole world at that time at $1,500,000,000; which is now (1910) about the amount of the electric-lighting investment in the United States. Incidentally a note remarks: "So unpleasant is the effect of the products of gas that in the new Madison Square Theatre every gas jet is ventilated by special tubes to carry away the products of combustion." In short, there is no aspect of the new problem to which Edison failed to apply his acutest powers; and the speed with which the new system was worked out and introduced was simply due to his initial mastery of all the factors in the older art. Luther Stieringer, an expert gas engineer and inventor, whose services were early enlisted206, once said that Edison knew more about gas than any other man he had ever met. The remark is an evidence of the kind of preparation Edison gave himself for his new task.
点击收听单词发音
1 lengthening | |
(时间或空间)延长,伸长( lengthen的现在分词 ); 加长 | |
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2 lighting | |
n.照明,光线的明暗,舞台灯光 | |
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3 tenaciously | |
坚持地 | |
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4 reigns | |
n.君主的统治( reign的名词复数 );君主统治时期;任期;当政期 | |
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5 supreme | |
adj.极度的,最重要的;至高的,最高的 | |
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6 veneration | |
n.尊敬,崇拜 | |
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7 benefactors | |
n.捐助者,施主( benefactor的名词复数 );恩人 | |
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8 generic | |
adj.一般的,普通的,共有的 | |
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9 adoption | |
n.采用,采纳,通过;收养 | |
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10 pall | |
v.覆盖,使平淡无味;n.柩衣,棺罩;棺材;帷幕 | |
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11 distinguished | |
adj.卓越的,杰出的,著名的 | |
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12 watt | |
n.瓦,瓦特 | |
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13 concurrent | |
adj.同时发生的,一致的 | |
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14 concur | |
v.同意,意见一致,互助,同时发生 | |
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15 sperm | |
n.精子,精液 | |
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16 metropolis | |
n.首府;大城市 | |
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17 petroleum | |
n.原油,石油 | |
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18 illuminating | |
a.富于启发性的,有助阐明的 | |
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19 mustered | |
v.集合,召集,集结(尤指部队)( muster的过去式和过去分词 );(自他人处)搜集某事物;聚集;激发 | |
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20 dwindled | |
v.逐渐变少或变小( dwindle的过去式和过去分词 ) | |
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21 incandescent | |
adj.遇热发光的, 白炽的,感情强烈的 | |
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22 analogous | |
adj.相似的;类似的 | |
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23 demonstration | |
n.表明,示范,论证,示威 | |
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24 demonstrations | |
证明( demonstration的名词复数 ); 表明; 表达; 游行示威 | |
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25 charcoal | |
n.炭,木炭,生物炭 | |
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26 labor | |
n.劳动,努力,工作,劳工;分娩;vi.劳动,努力,苦干;vt.详细分析;麻烦 | |
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27 rim | |
n.(圆物的)边,轮缘;边界 | |
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28 mere | |
adj.纯粹的;仅仅,只不过 | |
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29 zinc | |
n.锌;vt.在...上镀锌 | |
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30 embryo | |
n.胚胎,萌芽的事物 | |
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31 onward | |
adj.向前的,前进的;adv.向前,前进,在先 | |
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32 beacons | |
灯塔( beacon的名词复数 ); 烽火; 指路明灯; 无线电台或发射台 | |
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33 promising | |
adj.有希望的,有前途的 | |
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34 engender | |
v.产生,引起 | |
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35 furor | |
n.狂热;大骚动 | |
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36 speculation | |
n.思索,沉思;猜测;投机 | |
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37 ushered | |
v.引,领,陪同( usher的过去式和过去分词 ) | |
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38 calcium | |
n.钙(化学符号Ca) | |
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39 incandescence | |
n.白热,炽热;白炽 | |
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40 previously | |
adv.以前,先前(地) | |
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41 investigators | |
n.调查者,审查者( investigator的名词复数 ) | |
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42 investigator | |
n.研究者,调查者,审查者 | |
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43 physicists | |
物理学家( physicist的名词复数 ) | |
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44 attainment | |
n.达到,到达;[常pl.]成就,造诣 | |
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45 stimulus | |
n.刺激,刺激物,促进因素,引起兴奋的事物 | |
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46 entirely | |
ad.全部地,完整地;完全地,彻底地 | |
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47 impetus | |
n.推动,促进,刺激;推动力 | |
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48 lapse | |
n.过失,流逝,失效,抛弃信仰,间隔;vi.堕落,停止,失效,流逝;vt.使失效 | |
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49 faculties | |
n.能力( faculty的名词复数 );全体教职员;技巧;院 | |
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50 briefly | |
adv.简单地,简短地 | |
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51 determined | |
adj.坚定的;有决心的 | |
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52 deter | |
vt.阻止,使不敢,吓住 | |
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53 platinum | |
n.白金 | |
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54 noted | |
adj.著名的,知名的 | |
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55 tar | |
n.柏油,焦油;vt.涂或浇柏油/焦油于 | |
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56 chamber | |
n.房间,寝室;会议厅;议院;会所 | |
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57 metallic | |
adj.金属的;金属制的;含金属的;产金属的;像金属的 | |
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58 exhaustion | |
n.耗尽枯竭,疲惫,筋疲力尽,竭尽,详尽无遗的论述 | |
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59 joint | |
adj.联合的,共同的;n.关节,接合处;v.连接,贴合 | |
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60 mechanism | |
n.机械装置;机构,结构 | |
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61 combustion | |
n.燃烧;氧化;骚动 | |
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62 disintegration | |
n.分散,解体 | |
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63 evaporation | |
n.蒸发,消失 | |
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64 durable | |
adj.持久的,耐久的 | |
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65 subdivide | |
vt.细分(细区分,再划分,重分,叠分,分小类) | |
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66 fully | |
adv.完全地,全部地,彻底地;充分地 | |
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67 eminent | |
adj.显赫的,杰出的,有名的,优良的 | |
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68 incompatible | |
adj.不相容的,不协调的,不相配的 | |
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69 undoubtedly | |
adv.确实地,无疑地 | |
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70 sketch | |
n.草图;梗概;素描;v.素描;概述 | |
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71 legitimate | |
adj.合法的,合理的,合乎逻辑的;v.使合法 | |
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72 naught | |
n.无,零 [=nought] | |
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73 exponents | |
n.倡导者( exponent的名词复数 );说明者;指数;能手 | |
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74 jeers | |
n.操纵帆桁下部(使其上下的)索具;嘲讽( jeer的名词复数 )v.嘲笑( jeer的第三人称单数 ) | |
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75 ascertain | |
vt.发现,确定,查明,弄清 | |
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76 acoustic | |
adj.听觉的,声音的;(乐器)原声的 | |
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77 minor | |
adj.较小(少)的,较次要的;n.辅修学科;vi.辅修 | |
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78 specially | |
adv.特定地;特殊地;明确地 | |
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79 actively | |
adv.积极地,勤奋地 | |
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80 originality | |
n.创造力,独创性;新颖 | |
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81 disintegrated | |
v.(使)破裂[分裂,粉碎],(使)崩溃( disintegrate的过去式和过去分词 ) | |
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82 disintegrate | |
v.瓦解,解体,(使)碎裂,(使)粉碎 | |
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83 immediate | |
adj.立即的;直接的,最接近的;紧靠的 | |
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84 expedients | |
n.应急有效的,权宜之计的( expedient的名词复数 ) | |
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85 prevailing | |
adj.盛行的;占优势的;主要的 | |
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86 acting | |
n.演戏,行为,假装;adj.代理的,临时的,演出用的 | |
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87 refractory | |
adj.倔强的,难驾驭的 | |
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88 silicon | |
n.硅(旧名矽) | |
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89 brass | |
n.黄铜;黄铜器,铜管乐器 | |
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90 steadily | |
adv.稳定地;不变地;持续地 | |
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91 fixed | |
adj.固定的,不变的,准备好的;(计算机)固定的 | |
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92 inscription | |
n.(尤指石块上的)刻印文字,铭文,碑文 | |
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93 goblet | |
n.高脚酒杯 | |
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94 promptly | |
adv.及时地,敏捷地 | |
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95 founders | |
n.创始人( founder的名词复数 ) | |
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96 naval | |
adj.海军的,军舰的,船的 | |
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97 memorable | |
adj.值得回忆的,难忘的,特别的,显著的 | |
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98 subdividing | |
再分,细分( subdivide的现在分词 ) | |
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99 decided | |
adj.决定了的,坚决的;明显的,明确的 | |
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100 interfering | |
adj. 妨碍的 动词interfere的现在分词 | |
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101 laymen | |
门外汉,外行人( layman的名词复数 ); 普通教徒(有别于神职人员) | |
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102 essentially | |
adv.本质上,实质上,基本上 | |
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103 volts | |
n.(电压单位)伏特( volt的名词复数 ) | |
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104 sufficiently | |
adv.足够地,充分地 | |
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105 apparently | |
adv.显然地;表面上,似乎 | |
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106 copper | |
n.铜;铜币;铜器;adj.铜(制)的;(紫)铜色的 | |
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107 relatively | |
adv.比较...地,相对地 | |
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108 thereby | |
adv.因此,从而 | |
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109 filament | |
n.细丝;长丝;灯丝 | |
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110 susceptible | |
adj.过敏的,敏感的;易动感情的,易受感动的 | |
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111 filamentary | |
adj.细丝状的;细丝的;似丝的;单纤维的 | |
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112 perfectly | |
adv.完美地,无可非议地,彻底地 | |
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113 temerity | |
n.鲁莽,冒失 | |
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114 attenuated | |
v.(使)变细( attenuate的过去式和过去分词 );(使)变薄;(使)变小;减弱 | |
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115 filaments | |
n.(电灯泡的)灯丝( filament的名词复数 );丝极;细丝;丝状物 | |
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116 countless | |
adj.无数的,多得不计其数的 | |
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117 omission | |
n.省略,删节;遗漏或省略的事物,冗长 | |
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118 illustrated | |
adj. 有插图的,列举的 动词illustrate的过去式和过去分词 | |
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119 vertical | |
adj.垂直的,顶点的,纵向的;n.垂直物,垂直的位置 | |
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120 affected | |
adj.不自然的,假装的 | |
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121 interfered | |
v.干预( interfere的过去式和过去分词 );调停;妨碍;干涉 | |
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122 fervor | |
n.热诚;热心;炽热 | |
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123 vista | |
n.远景,深景,展望,回想 | |
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124 alluring | |
adj.吸引人的,迷人的 | |
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125 devoted | |
adj.忠诚的,忠实的,热心的,献身于...的 | |
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126 detailed | |
adj.详细的,详尽的,极注意细节的,完全的 | |
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127 alloys | |
n.合金( alloy的名词复数 ) | |
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128 vigor | |
n.活力,精力,元气 | |
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129 fusion | |
n.溶化;熔解;熔化状态,熔和;熔接 | |
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130 accomplished | |
adj.有才艺的;有造诣的;达到了的 | |
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131 exhausted | |
adj.极其疲惫的,精疲力尽的 | |
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132 radical | |
n.激进份子,原子团,根号;adj.根本的,激进的,彻底的 | |
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133 occluded | |
v.堵塞( occlude的过去式和过去分词 );阻隔;吸收(气体) | |
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134 fervent | |
adj.热的,热烈的,热情的 | |
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135 zeal | |
n.热心,热情,热忱 | |
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136 scanty | |
adj.缺乏的,仅有的,节省的,狭小的,不够的 | |
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137 thermal | |
adj.热的,由热造成的;保暖的 | |
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138 apparatus | |
n.装置,器械;器具,设备 | |
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139 potent | |
adj.强有力的,有权势的;有效力的 | |
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140 joints | |
接头( joint的名词复数 ); 关节; 公共场所(尤指价格低廉的饮食和娱乐场所) (非正式); 一块烤肉 (英式英语) | |
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141 simplicity | |
n.简单,简易;朴素;直率,单纯 | |
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142 durability | |
n.经久性,耐用性 | |
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143 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) | |
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144 reverted | |
恢复( revert的过去式和过去分词 ); 重提; 回到…上; 归还 | |
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145 requisite | |
adj.需要的,必不可少的;n.必需品 | |
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146 conclusively | |
adv.令人信服地,确凿地 | |
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147 deductions | |
扣除( deduction的名词复数 ); 结论; 扣除的量; 推演 | |
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148 bent | |
n.爱好,癖好;adj.弯的;决心的,一心的 | |
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149 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) | |
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150 justified | |
a.正当的,有理的 | |
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151 expenditure | |
n.(时间、劳力、金钱等)支出;使用,消耗 | |
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152 possessed | |
adj.疯狂的;拥有的,占有的 | |
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153 outlay | |
n.费用,经费,支出;v.花费 | |
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154 tenuous | |
adj.细薄的,稀薄的,空洞的 | |
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155 brittle | |
adj.易碎的;脆弱的;冷淡的;(声音)尖利的 | |
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156 triumphant | |
adj.胜利的,成功的;狂欢的,喜悦的 | |
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157 vindication | |
n.洗冤,证实 | |
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158 faculty | |
n.才能;学院,系;(学院或系的)全体教学人员 | |
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159 meritorious | |
adj.值得赞赏的 | |
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160 generator | |
n.发电机,发生器 | |
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161 necessitated | |
使…成为必要,需要( necessitate的过去式和过去分词 ) | |
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162 generators | |
n.发电机,发生器( generator的名词复数 );电力公司 | |
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163 investigation | |
n.调查,调查研究 | |
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164 complimentary | |
adj.赠送的,免费的,赞美的,恭维的 | |
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165 applied | |
adj.应用的;v.应用,适用 | |
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166 jersey | |
n.运动衫 | |
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167 herald | |
vt.预示...的来临,预告,宣布,欢迎 | |
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168 intensified | |
v.(使)增强, (使)加剧( intensify的过去式和过去分词 ) | |
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169 prominence | |
n.突出;显著;杰出;重要 | |
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170 saturated | |
a.饱和的,充满的 | |
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171 strands | |
n.(线、绳、金属线、毛发等的)股( strand的名词复数 );缕;海洋、湖或河的)岸;(观点、计划、故事等的)部份v.使滞留,使搁浅( strand的第三人称单数 ) | |
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172 twine | |
v.搓,织,编饰;(使)缠绕 | |
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173 cedar | |
n.雪松,香柏(木) | |
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174 maple | |
n.槭树,枫树,槭木 | |
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175 cork | |
n.软木,软木塞 | |
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176 cane | |
n.手杖,细长的茎,藤条;v.以杖击,以藤编制的 | |
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177 canes | |
n.(某些植物,如竹或甘蔗的)茎( cane的名词复数 );(用于制作家具等的)竹竿;竹杖 | |
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178 prodigious | |
adj.惊人的,奇妙的;异常的;巨大的;庞大的 | |
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179 omnivorous | |
adj.杂食的 | |
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180 phenomena | |
n.现象 | |
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181 binding | |
有约束力的,有效的,应遵守的 | |
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182 microscopic | |
adj.微小的,细微的,极小的,显微的 | |
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183 thoroughly | |
adv.完全地,彻底地,十足地 | |
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184 afterward | |
adv.后来;以后 | |
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185 procure | |
vt.获得,取得,促成;vi.拉皮条 | |
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186 positively | |
adv.明确地,断然,坚决地;实在,确实 | |
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187 humdrum | |
adj.单调的,乏味的 | |
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188 monotonous | |
adj.单调的,一成不变的,使人厌倦的 | |
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189 scrutiny | |
n.详细检查,仔细观察 | |
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190 pebble | |
n.卵石,小圆石 | |
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191 sifting | |
n.筛,过滤v.筛( sift的现在分词 );筛滤;细查;详审 | |
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192 exclusion | |
n.拒绝,排除,排斥,远足,远途旅行 | |
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193 lessen | |
vt.减少,减轻;缩小 | |
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194 prospectus | |
n.计划书;说明书;慕股书 | |
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195 casually | |
adv.漠不关心地,无动于衷地,不负责任地 | |
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196 astounding | |
adj.使人震惊的vt.使震惊,使大吃一惊astound的现在分词) | |
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197 inquiry | |
n.打听,询问,调查,查问 | |
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198 kerosene | |
n.(kerosine)煤油,火油 | |
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199 jotted | |
v.匆忙记下( jot的过去式和过去分词 );草草记下,匆匆记下 | |
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200 inconvenient | |
adj.不方便的,令人感到麻烦的 | |
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201 pointed | |
adj.尖的,直截了当的 | |
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202 accomplishment | |
n.完成,成就,(pl.)造诣,技能 | |
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203 graphic | |
adj.生动的,形象的,绘画的,文字的,图表的 | |
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204 graphically | |
adv.通过图表;生动地,轮廓分明地 | |
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205 dilettante | |
n.半瓶醋,业余爱好者 | |
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206 enlisted | |
adj.应募入伍的v.(使)入伍, (使)参军( enlist的过去式和过去分词 );获得(帮助或支持) | |
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