FRANELIN’S PLACE IN SCIENCE. 157 
made by Daniel Draper, director of the New York Meteorological Observatory 
in the Central Park, and published in his reports of that observatory for the years 
boy 2-73. | 
2d. Ofthe Gulf Stream. The existence of this current was long ago de- 
tected by the New England fishermen, but they had no idea of its magnificent 
proportions, its great geographical and climatological importance. These were 
first brought into view by Franklin. In a memoir read at a meeting of the 
American Philosophical Society, December, 1785, he states that while he was con- 
cerned in the management of the American Post-office an investigation was had 
respecting the cause of the long voyages made by the packet ships from England. 
The merchant ships made much shorter ones. ‘There happened to be then in 
London a Nantucket sea-captain of my acquaintance, Captain Folger, to whom I 
communicated the affair. He told me that the difference was owing to this, 
that the Rhode Island captains were acquainted with the Gulf Stream, while those 
of the Engli:h packets were not. ‘In crossing it we have sometiines met and 
spoken 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 three miles an hour, and advised them to cross it and get out of it.’ 
I then observed it was a pity no notice was taken of this current upon the charts, 
and requested him to mark it out for me, which he readily complied with. | pro- 
cured it to be engraved, by order from the General Post-office on the old chart of 
the Atlantic, and copies were sent down to Falmouth for the captains of the pack- 
ets. Having since crossed the stream several times in passing between America 
and Europe, I have been attentive to sundry circumstances relating to it by which 
to know when one is init. I annex hereto observations made with the thermom- 
eter in two voyages. It will appear from them that a thermometer may be a use- 
ful instrument to a navigator, since currents coming from the northward into 
southern seas will probably be found colder than the waters of those seas, as the 
currents from southern seas into northern are found warmer.”’ 
Though Franklin was not the discoverer of the Gulf Stream, he was the first 
to bring it prominently into notice, to cause a chart of it to be published, to de- 
tect its most important characteristic—its high temperature—to introduce the use 
of the thermometer, and to point out the importance of that instrument in navi- 
gation. 
In the short compass of this article I have not space to relate many of his 
minor experiments and observations. There is, however, one that deserves to be 
teferred to, from the influence it has had in optical science. ‘‘I took,” says 
Franklin, ‘‘a number of little square pieces of broadcloth from a tailors pattern 
card, of various colors.. They were black, deep blue, lighter blue, green, pur- 
ple, red, yellow, white, and other colors or shades of colors. I laid them all out 
upon the snow on a bright sunshiny morning. Ina few hours (I can not now 
be exact as to the time) the black, being most warmed by the sun, was sunk so 
_low as to be below the stroke of the sun’s rays; the dark blue almost as low; the 
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