SEVENTEENTH MEETING. 29 



the valley of the Don. He referred particularly to a creek 

 he passed almost every day, called 2nd or 3rd creek or 

 Cemetery Creek. Of this creek he proceeded to show the 

 process of erosion. From Bloor Street all the drainage runs 

 north, the creek was on an average, 50 feet below the level 

 of Bloor Street. It was about 25^ miles long, and 300 feet 

 wide. He had taken out one-eighth of an inch of sediment 

 when dried from a gallon of water. During fifteen days, this 

 creek flows down at the rate of four miles an hour, and every 

 gallon of water carries down ^ of a solid inch of sediment. 

 Calculating from these elements, it would take 70,000 years 

 to carry down the contents of the valley. This would be the 

 age of the valley of the Don. He had observed several of 

 these Don creeks and concluded that the average erosion of 

 the valley was about the same as it is now. He thought 

 there was no difference in the erosion of a creek where there 

 were trees and of one where there were no trees. All things 

 considered he thought the erosion was the same now as when 

 there was a primeval forest. 



The President thought that on some days there might be 

 fifty times the volume of water carried down that Mr. Harvey 

 had mentioned. It would then remove a considerable portion 

 of the bank. This would shorten the time considerably. He 

 had known at one flood, in the course of a few days eight 

 inches of sand deposited over several acres of the Don Valley. 



Mr. Elvins said : Of course all these valleys were cut 

 through the drift. The Don itself was cut through the drift. 

 In undisturbed portions of the drift, but by no means at the 

 bottom of it were found portions of trees of the same species, 

 as those now existing. These fossil remains being the same 

 as the present trees, it seemed to him impossible that time 

 required for the erosion of the Don could have been so long 

 as that given by Mr. Harvey. It was not likely that it ex- 

 ceeded 6,000 or 7,000 years. 



