THREE CRUISES OF THE “ BLAKE.” 
252 
The first scientific basis for the exploration of the Gulf 
Stream was undoubtedly due to Franklin. At the time he was 
Postmaster-General of the Colonies, his attention was called to 
the fact that the royal mail packets made much longer passages 
to and from Europe than the trading vessels of Massachusetts 
and Rhode Island. On talking the matter over with Captain 
Folger of Nantucket, he first learned the existence of a strong 
easterly current, of which the New England captains took 
advantage in going to Europe, and which they avoided by 
sailing a northerly course on the home voyage. Folger also 
called Franklin’s attention to the fact that this current was a 
warm one. He and Dr. Blagden becoming interested in the 
question, Franklin set out to ascertain the size of the current 
and its temperature. Soon after, Franklin published the first 
chart of the Gulf Stream (Fig. 173), for the benefit of navi- 
gators, from information obtained from Nantucket whalemen, 
who were extremely familiar with the Gulf Stream, its course, 
strength, and extent. 
From the time of Franklin until the problem of the Gulf 
Stream was again attacked, in 1845, by Franklin’s descendant, 
Prof. A. D. Bache of the United States Coast Survey, many 
ingenious theories were published, but nothing was added to our 
knowledge of the origin and structure of the Gulf Stream. 
Humboldt, Arago, and others attempted to trace in the Gulf 
Stream a secondary effect of the tradewinds, and of the rota- 
tion of the earth. The officers of arctic expeditions sent to 
Spitzbergen did not fail to see the effect of a mass of warm 
water passing northward, and Von Baer was among the first to 
consider this body of water as an eastern extension of the Gulf 
Stream.:. Meanwhile the arctic explorers of Baffin’s Bay and 
western Greenland found themselves baffled in their efforts to 
reach high latitudes by the powerful southerly current, carry- 
ing with it fields of ice or huge icebergs, which had found their 
way south below the southern limits of the Banks of Newfound- 
land, and even beyond the latitude of Cape Cod and Nantucket 
Shoals. 
1 It was noticed by Lescarbot, in 1605, both north and south of it the water of 
that far north there was a mass of warm Ње Atlantic was cooler. 
water moving towards the east, and that 
