Ginn — ON CANADIAN CAVERNS. 
213 
ON CANADIAN CAVERNS. 
By George D. Gibb, M.D., M.A., F.G.S., Member of the Canadian 
Institute. 
(Continued from ]}ago 179). 
21. — Probable Caverns at Chatham. 
The greater part of the main road from Carillon to Grenville, a 
distance of thii-teen miles on the northern banks of the Ottawa River, 
iTins over the Calciferous sand rock of the Lower Silurian formation. 
In many places the surface of the rock is exposed, and beyond the 
village of Chatham, towards Grenville, and even in Chatham, for a 
short distance, the road consists of the solid limestone rock. As the 
surface of the rock is more or less rough or uneven, the road is an 
uncomfortable one to travel over in a wheeled vehicle. On driving 
over that part of the rock just near Chatham, a tremendous loud 
rumbling noise is occasioned by the stage, which is not heard in 
other situations. This has been attributed to the presence of one or 
more large caverns situated beneath the road at this place : and, on 
making inquiry on the spot, 1 learnt that a prevalent opinion has long 
been entertained by t?ie country people and many intelligent persons 
in the neigbourhood, that a considerable cavern does exist in this 
part of the country in the place mentioned. On the many occasions 
that I have driven over this road, the loud rumbling noise has been, 
invariably observed by my fellow travellers as well as by myself. 
Some day an opening into the cavern may be discovered and the 
mystery solved. The main road is elevated and is probably from 
seventy to ninety feet above the level of the Ottawa River. 
22. — Calquhoun's Cavern, Lanark. 
The locality of this cavern is in the northern corner of tlie town- 
ship of Lanark, in the county of the same name, Western Canada, on 
the borders of the small river Mississippi, a branch of the Ottawa. A 
small branch of the former runs into this township from the neigh- 
bouring township of Ramsay, in a south westerly direction from the 
village of Bellamyville. The cave was discovered in the autumn of 
1824, by Mr. Colquhoun, the owner of the gTOund, who, when clear- 
ing his land, came upon a hole at the foot of a tree, which was the 
first indication of its presence, and his curiosity induced him to de- 
scend and examine it. A notice of this discovery appeared in a 
Canadian newspaper, in November, which was seen by Dr. Bigsby, 
then in Philadelphia, who wrote to Lieut. Robe, of the Royal Staff 
