THE HAMILTON ASSOCIATION. 99 
destructive disfigures the exterior wall by white or rusty patches. I 
have traced this rock all over the city, and I may be permitted to sug- 
gest that its presence, (together with the indurated Niagara shales— 
unfortunately also too frequently used) is by no means calculated to 
impress us with a favorable opinion of our building stones proper, or 
the dishonest contractors who are ever anxious to substitute the 
most indifferent material, provided it can be more cheaply obtained. 
I can never pass one of the churches in Hamilton without regretting 
that when the original edifice was erected I abstained from calling 
attention to what led to its collapse and caused the death of a coun- 
tryman of mine, poor Sullivan, a workman employed there. 
The durability of building stone is sometimes tested by sub- 
mitting 14 inch cubes to pressure between steel plates. Some rather 
unexpected results were reached in New York State about eight or 
nine years ago by experiments of this sort. While grey Gneiss and 
dark Sienite sustained a pressure of only 22,575 pounds to the square 
inch, the limestone from the Cobleskill quarries withstood a crush of 
27,407 pounds on an average, before breaking. It was also noticed 
that the same horizon displays considerable difference as regards 
texture, losing compactness and becoming soft and shaly. In the 
Upper Clinton green band at “The Jolley Cut” you may notice a 
thin wedge-shaped layer varying in thickness from perhaps 8 to 2% 
inches. At ‘“ The Bluff,” a little beyond the reservoir, the same 
bed is three feet or more thick. From the closeness of the grain 
and its compact texture it may be looked upon as a durable build- 
ing stonethere. Although impressions of Lingula are occasionally 
noticed on the surface they are not, however, injurious. I think it 
resists absorption of water in a remarkable degree, as likewise very 
considerable pressure. I hope to return to the subject of this paper 
on a future occasion. 
May 27th, 1892. 
NOTES ON OUR LOCAL BUILDING STONES (NO. II). 
When the freestone quarries, viz., the capping of the Medina 
series below the Niagara Escarpment, were worked some thirty or 
forty years ago, there were less overlying shales and clays to be 
dumped than now. Thisis quite true. The difficulty of obtaining 
access to this fine building material has considerably increased, 
while its value has not in like proportion. Here we have (assuming 
