J. E. Hilgard—Basin of the Gulf of Mexico. 289 
Tn 1855, a cross section from Cape Florida to the Bahama Banks, 
observed by Lieutenant Craven, U.S. N., developed the fact 
that the Strait is a comparatively shallow channel, a greatest 
hen after the close of the Civil War the Coast Survey 
resumed its former activity, under the administration of Pro- 
fessor Benjamin Peirce, soundings across the Florida and 
Yucatan Channels were obtained by Master R. Platt, U.S. N., 
accompanied by a dredging party under the direction of the 
late L. F. Pouriales, 
It was not, however, until the present Superintendent of the 
Coast Survey, C. P. Patterson, LL.D., organized a systematic 
mander Howell; U. S. N., on the west coast of Florida in com- 
paratively shallow water and was continued and brought to a 
Successful conclusion by Commander Sigsbee, U.S. N. (1875- 
78) in the Coast Survey Steamer Blake, accompanied by Pro 
essor A. Agassiz, who had charge of the biological explorations. 
The methods of sounding and obtaining temperatures at great 
depths as well as those of dredging have been described in the 
urvey Reports for several years, and more especially in 
4 work recently written by Commander Sigsbee, 
published by the U. S. Coast Survey. It will suffice to men- 
__ hon here that the method of sounding employed was that of 
ing a fine steel wire, indicated by Sir Wm. Thomson, with 
the mechanical appliances perfected by Commanders Belknap 
and Sigshee, of the U avy. j 
urning now to our model or map we perceive that the basin 
of the Gulf of Mexico is an oval connected with the general 
cean circulation by two outlets, the Yucatan Channel and 
the Florida Straits.’ 
nt area of the entire Gulf, cutting it off by a line from Cape 
— florida to Havana, is 595,000 square miles. Supposing the 
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