THE GULF STREAM. 387 



iu their extended use, only be at the command of Government vessels; but 

 the United States Navy oflQcers have done well to maintain their national 

 honour in their endeavours to elucidate their famous Current. 



Between the years 1845 and 1859, the United States Coast Department 

 instituted a series of soundings and temperature observations along and 

 across the course of the Stream, the operations being conducted in the 

 Corwin by Lieutenants Craven and Mafl&t, and Commander Sands. Their 

 observations in the Straits of Florida were so remarkable as to over-turn 

 all preconceived notions of the great depth and volume of the Stream, 

 though later investigation has shown that their work had need of revision. 



The first reliable soundings of the bed of the Stream, from Florida 

 Strait to George's Bank, were made by Commander Bartlett, U.S.N., in 

 the Blake, in 1881 and 1882. Those previously made were with rope or 

 registering devices, which in strong currents or great depths are unreliable. 

 The latest soundings have been made with wire, by which the depth 

 can in all cases be ascertained with certainty and accuracy. 



The general plan of exploration of the Gulf Stream, laid down in 1845, 

 was to observe the phenomena on sections perpendicular to its axis 

 from well determined points on the coast. In pursuance of this design, 

 numerous sections have since been run between the Western part of 

 Florida Strait and the shoals off Nantucket, extending from the shore to 

 beyond its outer limits. It is difficult to explain the nature of these 

 soundings and their results without diagrams; but they are, of course, 

 of more utility to the physical geographer than to the sailor. What 

 follows on this head is mainly derived from the Annual Reports of the 

 United States Coast and Geodetic Survey. 



(374.) In the Straits of Florida, as in the bend of a river, it is found 

 that the deepest water is along its concave or Southern and Western sides, 

 as will be readily seen by reference to the chart, and here the Stream 

 runs strongest. The following particulars of the more important sections 

 are taken from the latest (1893) charts published by the United States 

 Hydrographic Office. 



Between Kay West and Ha^?awa,'sounding operations were carried on 

 under Professor Mitchell in 1866 and 1867, in connection with laying 

 a telegraph cable. The distance between Sand Kay and Havana is 82^ 

 miles, and the following are the depths shown upon the chart at distances 

 of about 10 miles apart, going from N.N.E. to S.S.W. : — 



136 369 508 862 936 924 968 472 fathoms. 



It will be seen that the deepest water is on the Cuban side, over 900 

 fathoms being found within 7 miles of Havana. This characteristic is 

 followed all the way along the Cuban side and that of the Great Banks. 

 At Havana, as above shown, there is an abrupt descent of nearly a mile 

 within 7 miles of the shore, while on the side of the Tortugas and Kay 

 West the water is comparatively shallow and the descent gradual. 



Of this breadth of 82 miles, the Gulf Stream was found not to occupy 

 more than 40 miles on the Southern side of the channel, and Professor 

 Mitchell was led to conclude that the Gulf Stream here has a nearly 

 uniform velocity for a depth of 600 fathoms, although its temperature 



