On the Gulf Stream and contiguous currents. 353 
rent, that the great mechanical system of oceanic circulation is ap- 
parently maintained, and which, with the operation of like causes 
in the atmosphere, may be supposed to have a powerful influence 
upon the climate of western Europe. Were the influence of winds 
wholly unfelt upon the ocean, it is probable that the same system — 
would continue to be maintained, in all its essential features, by the 
mechanical influences of the earth’s rotation combined with an unsta- 
ble state of equilibrium. The energy of this rotative influence, by 
which the earth is flattened about twenty seven miles in its polar 
diameter, and the depressive force of which, in each polar basin, is 
equal to that of a column of mercury more than five thousand feet in 
height, is at least sufficient to maintain the existing movements and 
mechanical relations of the terrestrial fluids, under the various and 
continued oscillations to which these fluids are necessarily subjected. 
One fact, too important to be omitted here, will serve to demon- 
strate the course and identity of the great ice-current for more than 
half the distance from Cape Race in Newfoundland to the coast of 
Massachusetts. On the 7th of July, 1886, H. M. packet Express 
passed between two large ice islands to the southward of Nova Sco- 
tia, in lat. 43° 13’ N. lon. 61° 17’ W., temperature of the water 42 
degrees, depth 45 fathoms ; the most western of these icebergs being 
in lat. 43° 09’, lon. 61° 26’, or about 75 miles southwesterly from 
Sable Island. 
From the temperature of the sea upon the North American banks 
and soundings, and in some other positions which are deemed anal- 
ogous, it has been assumed that the mean temperature of the sea is 
lower on shoals than in deep water, but it seems difficult to account 
for such a result, unless upon the ground already mentioned. It 
has, indeed, been ascribed to radiation from the bottom ; and again, 
it has been denied that radiation from a non-luminous body can be 
carried on freely through the water, and as the colder particles have 
no tendency to rise towards the surface, it does not appear how the 
supposed reduction in the temperature of the bottom can materially 
affect a current of fifty or twenty fathoms in depth, which is derived 
from a foreign source ; for on none of these shoals or soundings, 1S 
the water permanently quiescent. Were it otherwise, we might rea- 
sonably expect a diminution of temperature on shoals in winter, and 
an increase in summer, with a permanent increase, if in tropical lati- 
tudes. 1am informed by George W. Blunt, Esq., who has made a 
course of regular thermometrical observations while crossing the At- 
Vol. XX XII.—No. 2. 
