HURON COUNTY. : 295 
through the sand of the ridge and through the peaty marsh soil between 
the ridge and the Lake, presenting an appearance of having been 
dropped from floating icebergs. About one mile south-west of Monroe- 
ville a eranite bowlder eight and a half feet long and five feet in breadth 
projects four feet ten inches above the black mould of the prairie soil; 
others somewhat smaller are found here and there, and in places the sur- 
face is thickly dotted with them. Careful examination was made, to de- 
termine the question whether any or all of these were dropped after the 
surface had assumed its present form. Many bowlders were found on the 
sand ridge presenting such an appearance as suggested the inference 
that they had been dropped upon the ridge, but an examination in every 
cage, where, it was certain that they had not been moved by human 
agency, showed that they were still resting upon the rock, or upon the clay 
or gravel wnderlying the ridge, so that instead of resting upon the sand, they 
are only partly buried by it. All the well-marked terraces at Berlin 
Heights have bowlders scattered over them—the lower terraces showing 
them in the greatest abundance—indicating that they were all a part of 
the original Drift, cut away into terraces by the wave action, which 
would naturally leave the bowlders as they are now found. On the prairie 
soil, north of the ridge, bowlders are scattered here and there, and in 
places the surface is profusely set with them; but they protruded from 
the soil in the greatest abundance.where the underlying rock or bowlder- 
clay came nearest to the surface... During a long search, prosecuted for 
the express purpose of settling this question, not a single bowlder was 
found in its original bed which was not resting upon the rock or the 
bowlder-clay. Every fact thus far observed tends to the conclusion that 
all of the bowlders were dropped before the sand ridge and the prairie 
soil was formed; but near the south-west corner of Berlin township, in a 
primitive forest, composed mainly of large oaks, a great number of bowl- 
ders was discovered resting wpon the undisturbed vegetable mould. 
Many of these were lifted out of their beds, and the soil explored to a 
considerable distance below them. It was found to be pure vegetable 
mould, extending apparently to the depth of several feet. Certainly 
every bowlder examined here, rested in and upon this black mould, and 
the inference seemed at first sight inevitable that they had in some man- 
ner been dropped uponit. A more careful study of their position and char- 
_ acter, however, leads to the conclusion that these also originally constituted 
a part of the floor of the old swamp, and were deposited in or upon the 
bowlder- -clay covered by it. They are now strictly superficial, resting on 
the soil, yery slightly embedded in it! If they were dropped upon the < 
| surface of the swamp, this must have occurred when it was covered with 
