Perhaps one of the commonest of the many errors made in speaking of marine9 things is that of confounding current with tide. Now tide, though a variable feature of the circulation of the waters near land, is fairly dependable. That is to say, the navigator may calculate by means of the moon’s age and the latitude10 of the place not only the time of high water, but knowing the mean height at full and change of the moon, he may and does ascertain11 to what height the water will rise, or how low it will fall at a certain place on a given date. True, a heavy gale12 of wind blowing steadily13 in or against the same direction of the ebbing14 or flowing tide will accelerate or retard15, raise or depress, that tide at the time; but these aberrations16, though most unpleasant oftentimes to riparian householders, are rarely of much hindrance17 or danger to navigation. This cannot be said of the currents of the sea. The tides have their limits assigned to them both inland and off-shore, although in the latter case it is almost impossible to tell exactly where their influence becomes merged18 in the vaster sway of the ocean currents, with all their unforeseen developments. The limits of tidal waters in rivers, on the other hand, being well under observation at all times, may be and are determined19 with the greatest exactitude.
With regard to the few instances of dependability among ocean currents, the first place will undoubtedly20 by common consent be given to the[321] Gulf21 Stream. Owing its existence primarily to the revolution of the earth upon its axis22, its outflow through the tortuous23 channel connecting the Gulf of Florida with the North Atlantic is more constant and steady in direction than any ebbing or flowing tide in the world, inasmuch as its “set” is invariably upon one course. Its rate is not so uniform, varying somewhat with the season, but in the narrowest part of the channel remaining fairly constant at about four knots an hour. Yet sail but a few score leagues into the Florida Gulf whence this great river in the sea takes its apparent rise, and its influence disappears! The mariner24 may seek there in vain for that swift, silent flow which in the Straits of Florida sweeps him north-eastward25 irresistibly26 in the teeth of the strongest gale. What has happened? Does the mighty27 stream drain westward28 into that great land-locked sea by hundreds of channels from the Equatorial regions, but far below the surface, and, obeying some all-compelling impulse, rise to the light upon reaching the Bahama Banks, pouring out its beneficent flood as it comes at the rate of a hundred miles per day? It sweeps into the broad Atlantic, and immediately spreads out into a breadth to which the Amazon is but a brooklet29, losing its velocity30 meanwhile, until, having skirted the North American coast as far as the Grand Banks, it rolls in sublime31 grandeur32 eastward towards these “fortunate isles33.” As it does so the mystery attendant upon it deepens. Its balmy presence cannot be mistaken, for the air on either side of it may be piercing in its keenness,[322] while immediately above it there is summer. A gale blowing at right angles to its course will raise that terrible combination of waves which gives alike to the “Western Ocean” and the “pitch of the Cape34” their evil reputation as the most dangerous in the world; and yet who among navigators has ever been able to determine what, if any, rate of speed it has in mid-Atlantic? Look through hundreds of log-books kept on board ships that are, perhaps, more carefully navigated36 than any others, the North Atlantic liners, and you shall not find a trace of the Gulf Stream “set” mentioned. In order to make this clear, it should be said that in all properly navigated ships the course steered37 and the speed made are carefully noted38 throughout the twenty-four hours; and this course, with distance run, calculated from the position accurately39 fixed40 by observation of the celestial41 bodies at the previous noon, gives the ship’s position by “dead reckoning.” The ship’s position being also found by the celestial bodies at the same time, the difference between the latter and the “dead reckoning” position should give the “set” and direction of the current for the twenty-four hours. And in vessels42 so carefully steered, and whose speed is so accurately known, as the great liners are, such current data are as trustworthy as any nautical43 data can be. But according to the records kept by these able navigators, there is no current setting eastward across the North Atlantic. Perhaps the explanation is that it is so very sluggish44 as to be unnoticeable, for those dreadful monuments of misfortune[323] to themselves and others, the derelict ships, have been known to drift completely backwards46 and forwards across the Atlantic, finding not only a current to carry them eastward, but its counter-current to carry them back again.
But who among us with the slightest smattering of physiography is there that is not assured that but for the genial47 warmth of this mighty silent sea-river our islands would revert48 to their condition at the glacial epoch49; who is there but feels a shiver of dread45 pass over his scalp when he contemplates50 the possibility of any diversion of its life-giving waters from our shores? The bare suggestion of such a calamity51 is most terrifying.
As steady and reliable in its operations is the great Equatorial current which, sweeping52 along the Line from east to westward, is doubtless the fountain and origin of the Gulf Stream, although its operations among that ring of islands guarding the entrance to the Mexican Gulf are involved in such obscurity that none may trace them out. And going farther south, we find the Agulhas current, beloved of homeward-bound sailing-ships round the Cape of Good Hope, pursuing its even, resistless course around the Southern Horn of Africa changelessly throughout the years. How its stubborn flow frets53 the stormy Southern Sea! No wonder that the early navigators doubling the Cape outward-bound, and fearing to go south, believed that some unthinkable demon54 held sway over those wild waves. The passage of Cape Horn from east to west holds the bad eminence55 to-day among seafarers of being the most[324] difficult in the world, but what the outward passage around the Cape of Storms must have been before men learned that it was possible to avoid the stream of the Agulhas current by going a few degrees south we of these later days can only imagine. What becomes of the Agulhas current when once it has poured its volume of Indian Ocean waters into the Atlantic? Does it sink below the surface some hundreds of fathoms56, and silently, smoothly57, glide58 south to the confines of the Antarctic ice barrier, or does it wander northward59 into warmer regions? In any case, it fulfils the one grand function of all currents, whether of air or water—the avoidance of stagnation60, the circulation of health among the nations of the earth.
Coming northward in the Pacific, let us note the counterpart of the Gulf Stream, the Kuro Siwo, or Black River of Japan, with the multitudinous isles of the East Indian Archipelago for its Caribbean Sea, and Nippon for its British Isles. It is, however, but a poor competitor in benevolence61 with our own Gulf Stream, as all those who know their Japan in winter can testify. Others there are that might be noted and classified if this aimed at being a scientific article, but these will suffice. These are surely wide fields enough for the imagination to rove in, wonderful depths of energy in plenty wherein the reverent62 and thoughtful mind may find all-sufficient food for its workings. Remembering that the known is but the fringe of the unknown, and that the secrets of the ocean are so well kept that man’s hand shall never fully35 tear aside the veil,[325] we may patiently ponder and wonder. That great sea of the ancients beyond whose portals, according to their wisdom, lay Cimmerian darkness—what keeps its almost tideless waters sweet? Unseen currents enter and leave by the Pillars of Hercules at differing levels, and could we but penetrate63 those dim regions we should doubtless find the ingress and egress64 of that incalculable mass of water proceeding65 continually, the one above the other, renewing from the exhaustless stores of the Atlantic the staleness of the great midland lake, itself apparently66 remaining in unchanging level.
But when all these great well-known movements of the ocean have been considered, there still remain an infinite number of minor67 divagations influenced by who knows what hidden causes. The submarine upheavals68 of central heat, when from out of her glowing entrails the old earth casts incandescent69 stores of lava70, raising the superincumbent mass of water for many square miles almost to boiling-point—who can estimate the effect that these throes have upon the trend of great areas of ocean? The almost infernal energy of those gyrating meteors of the tropics as they rage across the seas—how can any mind, however acute, assess the drag upon the whole body of surface water that is manifested thereby71? To say nothing of the displacement72 caused by the less violent but far more frequent stress laid upon the much-enduring sea by extra-tropical gales73, whereby the baffled mariner’s calculations are all overset, and his ship that should be careering safely in the[326] wide offing is suddenly dashed in ruins upon the iron-bound shore!
Great efforts have been made to lay down for the benefit of seafarers a comprehensive scheme of ocean currents all over the watery74 surface of the globe, but in the great majority of cases the guidance is delusive75, the advice untrustworthy, through no fault of the compilers. They have done their best, but mean results can never help particular needs. And so the wary76 mariner, as far as may be, trusts to the old-fashioned three “L’s,”—lead, log, and look-out; knowing full well how little reliance is to be placed in the majority of cases upon any advice soever concerning the mystery of ocean currents.
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1 phenomena | |
n.现象 | |
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2 tempted | |
v.怂恿(某人)干不正当的事;冒…的险(tempt的过去分词) | |
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3 meditating | |
a.沉思的,冥想的 | |
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4 investigators | |
n.调查者,审查者( investigator的名词复数 ) | |
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5 bestowed | |
赠给,授予( bestow的过去式和过去分词 ) | |
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6 possessed | |
adj.疯狂的;拥有的,占有的 | |
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7 alteration | |
n.变更,改变;蚀变 | |
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8 equilibrium | |
n.平衡,均衡,相称,均势,平静 | |
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9 marine | |
adj.海的;海生的;航海的;海事的;n.水兵 | |
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10 latitude | |
n.纬度,行动或言论的自由(范围),(pl.)地区 | |
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11 ascertain | |
vt.发现,确定,查明,弄清 | |
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12 gale | |
n.大风,强风,一阵闹声(尤指笑声等) | |
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13 steadily | |
adv.稳定地;不变地;持续地 | |
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14 ebbing | |
(指潮水)退( ebb的现在分词 ); 落; 减少; 衰落 | |
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15 retard | |
n.阻止,延迟;vt.妨碍,延迟,使减速 | |
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16 aberrations | |
n.偏差( aberration的名词复数 );差错;脱离常规;心理失常 | |
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17 hindrance | |
n.妨碍,障碍 | |
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18 merged | |
(使)混合( merge的过去式和过去分词 ); 相融; 融入; 渐渐消失在某物中 | |
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19 determined | |
adj.坚定的;有决心的 | |
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20 undoubtedly | |
adv.确实地,无疑地 | |
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21 gulf | |
n.海湾;深渊,鸿沟;分歧,隔阂 | |
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22 axis | |
n.轴,轴线,中心线;坐标轴,基准线 | |
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23 tortuous | |
adj.弯弯曲曲的,蜿蜒的 | |
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24 mariner | |
n.水手号不载人航天探测器,海员,航海者 | |
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25 eastward | |
adv.向东;adj.向东的;n.东方,东部 | |
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26 irresistibly | |
adv.无法抵抗地,不能自持地;极为诱惑人地 | |
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27 mighty | |
adj.强有力的;巨大的 | |
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28 westward | |
n.西方,西部;adj.西方的,向西的;adv.向西 | |
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29 brooklet | |
n. 细流, 小河 | |
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30 velocity | |
n.速度,速率 | |
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31 sublime | |
adj.崇高的,伟大的;极度的,不顾后果的 | |
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32 grandeur | |
n.伟大,崇高,宏伟,庄严,豪华 | |
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33 isles | |
岛( isle的名词复数 ) | |
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34 cape | |
n.海角,岬;披肩,短披风 | |
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35 fully | |
adv.完全地,全部地,彻底地;充分地 | |
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36 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 | |
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37 steered | |
v.驾驶( steer的过去式和过去分词 );操纵;控制;引导 | |
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38 noted | |
adj.著名的,知名的 | |
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39 accurately | |
adv.准确地,精确地 | |
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40 fixed | |
adj.固定的,不变的,准备好的;(计算机)固定的 | |
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41 celestial | |
adj.天体的;天上的 | |
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42 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 | |
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43 nautical | |
adj.海上的,航海的,船员的 | |
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44 sluggish | |
adj.懒惰的,迟钝的,无精打采的 | |
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45 dread | |
vt.担忧,忧虑;惧怕,不敢;n.担忧,畏惧 | |
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46 backwards | |
adv.往回地,向原处,倒,相反,前后倒置地 | |
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47 genial | |
adj.亲切的,和蔼的,愉快的,脾气好的 | |
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48 revert | |
v.恢复,复归,回到 | |
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49 epoch | |
n.(新)时代;历元 | |
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50 contemplates | |
深思,细想,仔细考虑( contemplate的第三人称单数 ); 注视,凝视; 考虑接受(发生某事的可能性); 深思熟虑,沉思,苦思冥想 | |
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51 calamity | |
n.灾害,祸患,不幸事件 | |
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52 sweeping | |
adj.范围广大的,一扫无遗的 | |
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53 frets | |
基质间片; 品丝(吉他等指板上定音的)( fret的名词复数 ) | |
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54 demon | |
n.魔鬼,恶魔 | |
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55 eminence | |
n.卓越,显赫;高地,高处;名家 | |
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56 fathoms | |
英寻( fathom的名词复数 ) | |
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57 smoothly | |
adv.平滑地,顺利地,流利地,流畅地 | |
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58 glide | |
n./v.溜,滑行;(时间)消逝 | |
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59 northward | |
adv.向北;n.北方的地区 | |
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60 stagnation | |
n. 停滞 | |
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61 benevolence | |
n.慈悲,捐助 | |
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62 reverent | |
adj.恭敬的,虔诚的 | |
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63 penetrate | |
v.透(渗)入;刺入,刺穿;洞察,了解 | |
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64 egress | |
n.出去;出口 | |
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65 proceeding | |
n.行动,进行,(pl.)会议录,学报 | |
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66 apparently | |
adv.显然地;表面上,似乎 | |
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67 minor | |
adj.较小(少)的,较次要的;n.辅修学科;vi.辅修 | |
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68 upheavals | |
突然的巨变( upheaval的名词复数 ); 大动荡; 大变动; 胀起 | |
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69 incandescent | |
adj.遇热发光的, 白炽的,感情强烈的 | |
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70 lava | |
n.熔岩,火山岩 | |
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71 thereby | |
adv.因此,从而 | |
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72 displacement | |
n.移置,取代,位移,排水量 | |
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73 gales | |
龙猫 | |
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74 watery | |
adj.有水的,水汪汪的;湿的,湿润的 | |
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75 delusive | |
adj.欺骗的,妄想的 | |
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76 wary | |
adj.谨慎的,机警的,小心的 | |
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