208 
GEOLOGY OF THE FIRST DISTRICT. 
by their having been dragged over rocks and gravelly earth in one steady position. On exa¬ 
mination, they exhibit scratches and furrows on the abraded part; and if among the minerals 
composing the rock, there happened to be pebbles of feldspar or quartz, which was not un¬ 
common, they usually appeared less worn than the rest of the stone, and preserved the more 
tender parts of the mass in a ridge extending some inches. When several of these pebbles 
happened to be in one block, the preserved ridges were on the same side of the pebbles, so 
that it is easy to determine which part of the mass moved forward in the act of wearing. I have 
caused blocks with the above appearances, and weighing fifteen tons, to be split up ; and there 
were many others dug from the same place and vicinity, weighing from ten to fifty hundred 
weight, some of which were two hundred feet above the stream of water in the vicinity. 
These boulders are found not only on the surface, but many feet below, in a hard compound 
of clay, sand and gravel. One block of more than thirty hundred weight, marked and worn as 
above described, was dug out of a well at a depth of twenty-four feet. Boulders with these 
marks upon them I have seen not only in this town (Vernon, Conn.), but in Manchester and 
Ellington (Conn.), and in Wilbraham (Mass.). 
“ I think we cannot account for these appearances, unless we call in the aid of ice along 
with water ; and that they have been worn, by being suspended and carried in masses of ice 
over rocks and earth under water.”* 
Smoothed, scratched and furrowed rocks have been observed in Europe, where observa 
tions on this subject were first made ; but they are not common there, as in the northern parts 
of the United States in North America. 
Scratches and smoothed rocks have been observed by MM. Brongniart and Berzelius in 
Sweden and Norway, and particularly in the vicinity of Hogdale ;t and “Monsieur Sefs- 
troom,” says the distinguished Berzelius, “ has found that the northeast part of the mountains 
of Sweden are, throughout, rounded and worn from the base to the summit, so as to resem¬ 
ble at a distance sacks of wool piled upon each other. The southwest side of these mountains 
present almost fresh fractures of the rocks, with their angles rounded little or none.”j: 
In Scotland, Sir James Hall noticed them many years ago on greenstone and other rocks, 
with a direction northwest and southeast, in the vicinity of Edinburgh. He says, “ Where 
a mass of rock has been followed under ground to where its surface has been protected by a 
covering of clay, it is found to resemble a wet road, along which a number of heavy and irre¬ 
gular bodies have been recently dragged; indicating that every block that passed, had left its 
trace behind.” They agree generally in parallelism, with a few deviations, and agree in 
direction to the ridges and valleys and large features of the district. Fifteen examples are 
given on a map of the Costorphine hills. In the immediate neighborhood, the direction of 
the current was from the west, conforming to the hills of the estuary of the Forth ; but near 
Sterling, and in other places in that region, it was from the northwest.^ 
* American Journal of Science, Vol. 10, p. 217. 
t Brongniart. Terrains de I’dcorce du globe. Paris, 1829, p. 82. 
t Hitchcock’s Elementary Geology, p. 191. 
^ Transactions of the Royal Society of Edinburgh, Vol. 7; and Buckland, Rel. Diluvianae, p. 202 to 205. 
