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GEOLOGY OF THE FIRST DISTRICT. 
Prof. Hitchcock has shown that the direction of transportation of the boulders in the western 
part of Massachusetts was from the northwest, and in other parts variable, but generally from 
a northward direciion,* 
Dr. Jackson has shown that in Rhode Island, the transport was nearly north and south.! 
He has also shown, that in Maine, the general course was from the north, and a little west 
of north.! 
Boulders are very common east of the Blue ridge, as far south as Baltimore and Washing¬ 
ton. In grading a street in Baltimore, it was necessary to cut through a pebble bank and 
solid rock in place. The rock sloped away gradually to the north, and in the direction of the 
dip. “ At the point of the ridge on the south side, is a sudden pitch from the shelving or 
overhanging of the rock. From this point to the extremity of the section to the south, which 
is about sixty paces, the bank is filled with rolled pebbles, which, immediately at the pitch 
of the rock, appear as having been thrown down by cart-loads. From a strict examination 
of the whole section, it appears as if the pebbles were driven over the surface or north slope 
of the hill by a powerful current, until they had arrived at this sudden pitch, when they were 
let fall, or precipitated to the bottom.”^ The proofs are positive that the pebbles were brought 
and deposited by a powerful current from the north.|1 They consist of masses of granite, 
greenstone, and mica slate. These rocks exist in place only to the north, and from one to 
three miles distant.il 
In Virginia, Prof. Rodgers has described small boulders, or large pebbles, among the 
superficial sands.Tl 
Boulders and drift, like those of the Northern States, are extremely rare in the Middle and 
Southern States, except as gravel and sand, some of which have been transported, if we 
may judge from their materials, from far to the north. Pebbles of primary rocks are found 
in the Mississippi valley as far south as Louisiana, where I observed them, and Dr. Drake 
has described them at Natchez.** 
Dr. Bigsby, in describing the country around Lake Huron, speaking of boulders and 
erratic blocks, says: 
“ These fragments are incredibly numerous in Lake Huron, and may be divided into two 
geological classes, the foreign and the native. The former are more plentiful, and are round 
and smooth. They are seen every where, but are collected principally in the interior of the 
coasts and islands, either in confused heaps, or in parallel ridges, and crowning the highest 
acclivities in great numbers, and the fragments are of various dimensions. They belong 
almost exclusively to the older orders of rocks, and are thereforeft of a northern origin. 
* Geological Report of Massachusetts, 1841. ' t Geological Report of Rhode Island, 1839. 
t Geological Reports of Maine, 1837, 1838. ^ Hayden’s Geological Essays, pp. 47, 48, 49. 
II Hayden’s Geological Essays, ibidem; where the facts observed are detailed at length to prove his conclusions. 
IT Geological Reconnoisance of Virginia, 1836, p. 13. ** Silliman’s Journal, Vol. 29. 
+t This conclusion, indicated by the word therefore, would not be deemed satisfactory without explanation. The rocks in every 
direction, except to the northward, are known, for many hundreds of miles, to be transition, secondary, and quaternary formations, 
to the lowest levels to which man has had access. (Mather.) 
