p. 20

1827.

-20-

The second Rock is black bituminous slate. It overlies the lime rock above described, and forms the bank of the river as far down as I have been (ten miles); and is seen in the bottom and banks of numerous creeks, which enter the river from the north. This rock is said to be the same as that found at Pittsburgh overlaying the canal; It is therefore expected that coal may be found under it here. But boring has been tried near New Albany, 300 feet deep without finding either coal or salt. A spring that comes through this slate rock, near where the boring was made, contains a considerable quantity of sulphuretted hydrogen gas; and the gas is continually rising through the waters of the spring. The smell of the gas is perceived at some distance from the spring. I have seen no petrifactions in the slate rocks. It sometimes contains small masses of sulphuret or iron, disseminated through it. The lime rock above mentioned with occasional patches of this slate is the rock to be excavated in the construction of the canal.

The 3rd rock in order is the sand rock. It is of a yellowish and sometimes of a blue color. It has a compact texture, and a laminated structure. It forms the hilly country west of the rapids called the knobs; and from one of these hills the stone for the face of the lock walls is quarried. It contains but few petrifactions. The minerals are quartz crystals of a yellowish color, calcareous spar and a sulphate of magnesia, this salt may be seen coating some of the stones, brought here for the lock, in the state of a florescence. The same rock is in some of the highest knobs overlaid by another lime rock. At the quarry this lime rock is about 20 feet thick. And this makes the fourth rock which I have mentioned. The alluvium about the canal is chiefly blue and yellow clay, mixed with sand and gravel. It contains half decayed log