CHARTING THE RIVER 111 



Atlantic River. With Folger's advice he prepared a chart of 

 the Gulf Stream. This was the first current chart of the North 

 Atlantic designed to aid navigation rather than to support or 

 confound scientific speculation. It is traditionally true that 

 sailormen are conservative and slow to adopt new ideas, and 

 when Franklin's chart was published in 1770 the Falmouth 

 sea captains characteristically refused to use it. Franklin 

 wrote: 



'There happened then to be in London a Nantucket sea 

 captain of my acquaintance, to whom I communicated the 

 affair. He told me he believed the fact to be true, but the dif- 

 ference was owing to this, that the Rhode Island captains were 

 acquainted with the Gulf Stream, while those of the English 

 packets were not. We are well acquainted with that stream, 

 because in our pursuit of whales, which keep near the sides of 

 it but are not met within it, we run along the side and fre- 

 quently cross it to change our side; and in crossing it have 

 sometimes met and spoke with those packets who were in the 

 middle of it and stemming it. We have informed them that 

 they were stemming a current that was against them to the 

 value of 3 miles an hour and advised them to cross it, but they 

 were too wise to be councelled by simple American fisher- 

 men. When the winds are hght," he added, ''they are carried 

 back by the current more than they are forwarded by the 

 wind, and if the wind be good the subtraction of 70 miles a 

 day from their course is of some importance." 



Benjamin Franklin marked a turning point in the mapping 

 of salt waters, the plotting of the Ocean River, when he pub- 

 lished his chart for the General Post Office. Before this, knowl- 

 edge of the ocean had grown by the spoken word and by the 

 slow piecing together of scattered information from many 

 sources. But a new impetus was beginning to be felt; and as 

 time went on science was to go about the inquiry in its own 

 logical and methodical way, and to seek not only facts but 



