GULF STREAM, CLIMATES, AND COMMERCE. 



73 



York amounted in value to two millions and a half; from 

 Pennsylvania, to ^3,820,000; and from Charleston alone, to 

 ^'o,8o4:,000. But in 1795— by which time the Gulf Stream 

 began to be as well understood by navigators as it now is, 

 and the average passages from Europe to the north were 

 shortened nearly one -half, while those to the south remained 

 about the same — the customs at Philadelphia alone amounted 

 to ^2,941,000,* or more than one-half of those collected in all 

 the states together. 



190. Tlie shortening of voyages. — Nor did the effect of the 

 doctor's discovery end here. Before it was made, the Gulf 

 Stream was altogether insidious in its effects. By it, vessels 

 were often drifted many miles out of their course without know- 

 ing it ; and in bad and cloudy weather, when many days would 

 intervene from one observation to another, the set of the current, 

 though really felt but for a few hours during the interval, could 

 only be proportioned out equally among the whole number of 

 daj's. Therefore navigators could have only very vague ideas 

 either as to the strength or the actual limits of the Gulf Stream, 

 until they were marked out to the Nantucket fishermen by the 

 whales, or made known by Captain Folger to Dr. Franklin. 

 The discovery, therefore, of its high temperature assured the 

 navigator of the presence of a current of surprising velocity, and 

 which, now turned to certain account, would hasten, as it had 

 retarded, his voyage in a wonderful degree. Such, at the present 

 day, is the degree of perfection to which nautical tables and 

 instruments have been brought, that the navigator may now 

 detect, and with great certainty, every current that thwarts his 



* Value of Exports in Dollars.^ 



' Doc. No. 330, H. R., 2nd Session. 25th Congress. Some of its statements do not agree with 

 those taken from M'Pherson, and previously quoted. 



