The limestones in the bottom of a certain portion of lake Huron are undergoing a peculiar kind of erosion, which, from want of better terms to describe the process, may be called honeycombing and pitting.
The portion of the lake in which this phenomenon is most prevalent is that around Grand Manitoulin island, the Indian peninsula and in Big gap, which lies between them and connects the main body of the lake with Georgian bay. This curious form of erosion appears to be progressing most rapidly under a considerable depth of water, say, from 50 or 100 feet, down to greater depths, but it may also be going on in shallower water. The existence of the honeycombed limestone all over the bottom of this part of lake Huron is well known to every one living in the vicinity, and especially to the fishermen, to whom . . .