On the Physical Geology of the United States, §c. 17 
carries the gulf-weed and other floating bodies, and finally col- 
lects them in the centre of the great eddy of the Atlantic be- 
tween the Cape de Verd, the Azores and Bahama Islands. This 
tract of the ocean has been known for more than three hundred 
and fifty years to be covered with such quantities of floating sea- 
weed, plants, wood, &c. as frequently to impede the passage of 
ships. These floating bodies are supposed to circle around in 
this grand eddy (which is said to occupy a million of square 
miles, called the grassy sea and Sargasso sea) until they morn 
water logged, loaded with marine shells, or decayed, and sin 
The transport by the polar currents during the drift wae is 
believed to be satisfactorily established ; and it has been shown 
to be highly probable, perhaps almost certain, that the phenome- 
na of the drift deposits are conformable to the action of the polar 
and equatorial currents. 'The phenomena of the transportation 
of the materials of the more ancient formations, have not been 
studied so attentively as to demonstrate the same sources and di- 
rections of transportation, but we may infer it as probable in a 
very high degree, that large quantities of earthy materials were 
transported by the flow of the polar currents over the barren and 
rocky regions in America, Europe, New Zealand, &c. where 
from the operation of physical causes the currents would flow 
from the poles towards the equator with a less depth and greater 
velocity than on other parts of the earth.t We may also infer 
it from the fact that the thicker masses of the coarser sediment- 
ary rocks that are not calcareous, have been deposited in those 
parts where the polar currents in the United States must neces- 
sarily have flowed, when most of the continent was buried be- 
neath the waters of the ocean. ‘Those parts of the earth over 
which the polar currents are supposed to have flowed in ancient 
times, and from which they are supposed to have washed away 
the materials of the sedimentary rocks, are represented by all 
travellers as barren, unproductive, rocky and inhospitable wastes. 
* Natural History of New York, Part IV, Geology of Ist District, by W. W. 
Mather, pp. 295-296. Vide Lt. Maury’s paper on ocean currents for ‘a more full 
description ; Army and Navy Chronicle, IIL, pp- 661-667 ; Southern Literary Mes- 
senger, Vol. X, No. 7, July, 1844; and American Journal of Science and Arts 
Vol. xtvit, p. 161. 
t The reasons dee this supposition will he treated of in the discussion of the” 
pA ed of the continents above the oce 
Vol. x11x, No. paren as 1845. 3 
