DRIFT DIVISION. 
197 
coast of Yorkshire, and on the hills in Derbyshire, they are abundant. Some of them seem 
to have come from distant countries, and probably from Scandinavia. They are generally 
rounded ; others come from the mountains of England ; and although the rocks are much more 
tender than the preceding, their edges and angles are preserved.* 
The investigations in England, within a few years, have shown that the causes that have 
spread the drift deposits have been influenced by the relative levels and topographical features 
of the country, so far as never to cross the high ranges of hills and mountains, except at their 
lowest points, or by sweeping around their ends.f The same fact has been observed in the 
Alps and country around, each kind of rock following its respective valley.J 
In Iceland, an island supposed to be entirely volcanic, blocks of granite, containing many 
cubic yards, are said to have been found on the most elevated points.§ 
In South America, large blocks of granite have been found on the mountains of Potosi; and 
it is not known in place nearer than Tucuman, a distance of four hundred leagues.§ 
In India, enormous blocks of granite are cited as being piled on each other in the district of 
Hyderbad, in 17° north latitude.^ 
Prof. Struder states, that in the hill country at the foot of the Himalayah mountains in 
India, erratic boulders occur.|| 
Darwin and others have observed boulders and erratic blocks in great numbers in South 
America, between Cape Horn and the forty-first degree of south latitude.! 
De la Beche and Prof. Hovey describe diluvial detritus as abundant in Jamaica, and 
especially on the plain around Kingston, in the West Indies, and that it appears to have been 
drifted from the north.1 
The facts above narrated constitute one train of evidence in regard to the direction in which 
the drift deposits have been transported in the eastern part of New-York in particular, and 
in the United States and other parts of the world generally. Another train of evidence bear¬ 
ing on this subject also, is recognized in the smoothed and scratched surfaces of rocks in 
place, on mountains, in valleys, and over extensive plains; and this also affords the same 
kind of presumptive evidence of the direction and mode of transport as the other, but in a still 
more striking manner. 
♦ Sedgwick, Annals of Philosophy, April and July, 1825 ; and Buckland, Rel. Diluvianse, pp. 202, 203. For a more parti¬ 
cular account of those of England, vide De la Beche’s Manual, p. 160; Conybeare and Phillips’ Geology of England and Wales j 
Phillip’s Treatise on Geology, &c. 
t Phillips, Treatise on Geology, 1838, p. 209; and Encyclopaedia Britannica, seventh edition. 
J Phillips, Treatise on Geology, p. 207. 
^ Brongniart. Terrains de I’ecorce du globe. Paris, 1829, p. 83. 
il Hitchcock’s Elementary Geology, p. 186. 
^ Lyell’s Elements of Geology. Philadelphia, 1839, pp. 86 to 89. 
