THE GULF STREAM.] 



METEOROLOGY. 



1157 





Franklin having extracted this intelligence from the 

 whaling captain, got him to draw a chart of the gulf < 

 stream to the best of his ability. The chart was drawn; 

 Franklin had it printed; and copies were sent to the Fal- 

 mouth captains. They, however, were foolish enough to 

 pay no heed to its teachings ; nor did they profit for 

 many years after by the knowledge of the gulf stream. 

 Though the date of Franklin's discovery was 1775, yet a 

 knowledge of the gulf stream was not generally diffused 

 and acted upon until fifteen years later. Not the least 

 extraordinary fact in connection with the gulf stream, is 

 the sharpness of its line of demarcation. No river im- 

 prisoned between two scarped rocky banks could flow in 

 channel more defined. "If," remarked the American 

 author, Jonathan Williams, "these strips of water had 

 been distinguished by colours of red, white, and blue, 

 they could not be more distinctly discovered than they 

 are by the thermometer." " And he might have added," 

 remarks Maury, " nor could they have marked the posi- 

 tion of the ship more clearly." 



The notion prevails among sailors that the gulf stream 

 is the great storm breeder of the Atlantic the father of 

 storms ; and, indeed, the tempests which follow in its 

 course, or on its borders, warrant that designation. What 

 are the indications of theory in this respect 1 Had the 

 Atlantic been still an untravelled waste, and the existence 

 of a gulf stream, such as we now know it, been pro- 

 pounded as the basis of discussion, would not the theorist 

 have predicted that storms must originate in the meeting 

 of the hot, moist atmosphere, which hovers over the 

 ocean tract of seething waters, from the fiery shores of 

 Mexico and the Caribbean Sea, mixed with the chilling 

 blasts of the north i What torrents of water must result 

 from tho condensation of the tepid mists what stupen- 

 dous electrical force must be brought into operation ! 



If the gulf stream, by its impulsive flow, sometimes 

 impedes the mariner, and drives his ship from the de- 

 sired course, it nevertheless affords a compensation, not 

 i 'tily in assisting to propel ship* sailing in the direction 

 of its course, but in affording a genial climate to the 

 weather-beaten mariner, frozen and benumbed by the 

 shivering blasts of the regions outside its channel. " No 

 part of the world," says the writer, to whom we are 

 largely indebted for much that in these pages concerns 

 ocean currents and ocean climatology " no part of the 

 world," remarks Maury, "affords a more difficult or 

 dangeroui navigation than the approaches of our (the 

 American) coast in winter." Before the warmth of the 

 pulf stream was known, a voyage for this reason from 

 Europe to New England, New York, and even to tho 

 capes of the Delaware or Chesapeake, was many times 

 more trying, difficult, and dangerous than it now is. 

 In making this part of the coast, vessels are frequently 

 met by shore-storms ami gales which mock the seaman's 

 strength, and set at nought his skill. In a little while, 

 his b irk becomes a mass of ice, and his crew frosted and 

 helpless. She remains obedient only to her helm, and is 

 kept away for the gulf stream. After a few hours' run 

 he reaches its edge, and almost at the next bound, 

 passes from the midst of winter into a sea at summer- 

 heat. Now the ice disappears from his apparel : the 

 sailor bathes his stiffened limbs in tepid water ; feeling 

 himself invigorated and refreshed with the genial warmth 

 about him, he realises out at sea, the fable of Antaeus 

 and his mother Earth. He rises up and attempts to 

 make his port again ; and is again as rudely met, and 

 beaten back from the north-west ; but each time that he 

 is driven off from the contest, he arises forth from this 

 stream, like the ancient son of Neptune, stronger and 

 stronger ; until after many days his freshened strength 

 jirfvaiU, and he at last may enter his haven in safety ; 

 but in the contest he sometimes falls to rise no more, for 

 it is often terrible. Many ships annually founder in 

 gales ; and we might name instances, for they are 

 nut miioiiiiMon, in which vessels bound to Norfolk or 

 Baltimore', with their crews enervated in tropical cli- 

 mates, have encountered, as far down as the Cape of Vir- 

 ginia, snow-storms that have driven them back into the 

 gulf stream, times and again ; and have kept them thus 



out for forty, fifty, and even for sixty daya, trying to 

 make an anchorage. 



Nevertheless, the presence of the warm waters in the 

 gulf stream, with their summer-haat in mid-winter, off 

 the shores of New England, is a great boon to naviga- 

 tion. At this season of the year especially, the number 

 of wrecks and loss of life along the Atlantic sea-board are 

 frightful. The month's average of wrecks lias been as 

 high as three a-day. How many escape by seeking re- 

 fuge from the cold, in the warm waters of the gulf 

 stream, is a matter of conjecture. Suffice it to say, tliat 

 before this temperature was known, vessels thus dis- 

 tressed knew of no place of refuge short of the West 

 Indies ; and the newspapers of that day Franklin's 

 Pennsylvania Gazette among them inform us, that it was 

 no uncommon occurrence for vessels bound to the capes 

 of Delaware in winter to be blown off, and to go to tho 

 West Indies, and there wait for the return of spring, be- 

 fore they would attempt another approach towards their 

 destination. 



The gulf stream is the largest known oceanic current ; 

 it has been perhaps more fully studied than any other, 

 and its teachings may, therefore, be appropriately re- 

 garded as the type of the rest. We have seen how power- 

 ful and extensive are its effects ; we have seen a few of 

 the purposes to which it ministers. The ocean is full of 

 streams similar to this, each taking its well-defined 

 course, carrying its own temperature, clad with its own 

 fauna and flora, peopled with its own denizens. Thoughts 

 like these prove how false and unfounded is the expres- 

 sion, ocean waste, so commonly applied. The ocean has 

 its regions, its valleys, and its mountains climate and 

 varied inhabitants no less than the earth. 



OTIIKIC i >C-KANIC CURRENTS. The Mediterranean. It 

 has long been known that an upper or sailing current 

 constantly sets into the Mediterranean through the 

 Straits of Gibraltar. What, then, becomes of the water 

 of the current ( That water must either be dissipated by 

 evaporation, or there must be a second or back-current. 



The existence of this under-current was first demon- 

 strated very curiously in 1712. At that time, Franco 

 being at war with Holland, M. L'Aigle commanded ;> 

 French privateer, called the Ph&nijc of Mitrsfillcx. 

 Near Ceuta, this privateer gave chase to a Dutch ship 

 bound to Holland came up with her, delivered one 

 broadside, when the Dutch ship went down. A few days 

 later, the sunken ship, with all her cargo of brandy and 

 oil, came to light again ; but this took place on the coast 

 of Tangier, at least four leagues westward of the place 

 where the ship went down, and in a direction quite op- 

 posite to that of tho upper or navigable current. This 

 well-authenticated case was communicated to the Royal 

 Society in 1724. 



' 'urrcnts of the Red Kca Precisely similar to the 

 Mediterranean currents, just described, are those of the 

 Red Sea. The necessity of a free change of waters here 

 is even more decided than in the Mediterranean ; the 

 sea is not only shallower, and subjected to a more power- 

 ful evaporation, but its waters are not freshened by the 

 afflux of any rivers. It has been calculated by Dr. 

 I'.nist, that, taking into consideration the mean evapora- 

 tion on every part of the surface of the Red Sea, a 

 sheet of water, eight feet thick, and equal in superficial 

 area to the whole extent of the surface of that sea, is 

 raised in vapour annually. When this enormous rate of 

 evaporation is considered, the necessity for a continuous 

 interchange of water between the Red Sea and the ex- 

 ternal ocean will be evident. If the Red Sea outlet were 

 choked up, so that ingress and egress were no longer 

 possible, the evaporation of about a thousand years 

 would, it is calculated, completely dry it up. 



Currents of the Indian Ocean. Many thermal currents 

 originate in the Indian Ocean. Amongst the foremost of 

 these is the Mozambique current ; another of these cur- 

 rents, first escaping from the Straits of Malacca, and 

 being swollen by warm streams from the Java and 

 Chinese Seas, flows out into the Pacific between the 

 Philippines and the Asiatic shores. Passing thence to- 

 wards the Aleutian Isles, it ultimately loses itself on the 



