244 TRANSACTIONS OF THE CANADIAN INSTITUTE. [VOL. I. 



on the fact that the depth of water at about one mile from shore is 48 

 feet, — I verified this fact myself last summer, so that there has been little 

 change in 40 years, — and this he considers to be below the depth at which 

 wave action would be felt, or produce much effect. And this seems rea- 

 sonable, for at a distance of about 2000 feet from shore we meet with a 

 ridge, the top of which is only about 26 feet below the surface, although 

 on either side it quickly falls away to 33 feet. Now, if the waves had 

 much of an erosive effect at over 26 feet in depth, it would probably remove 

 the top of this ridge, but I found it there last summer just where Mr. 

 Rust found it several years ago when taking soundings of that part of 

 the lake. 



But, on the other hand, it occurs to me that if the cliff had formerly 

 extended only a few hundred or even a thousand feet farther south than at 

 present, the bar which now encloses Ashbridge's Bay, would have been 

 driven right on the mainland and have formed a beach, as there ap- 

 pears to have been no stream there sufficient to head it off, as the 

 Don might be capable of doing when it got further west. However, 

 this is not a point of vital importance to the existence of the Island. 



It may be claimed that storms from the west would have a coun- 

 teracting influence. Of course they would, but only in the ratio of 

 40 : 180, other things being equal. And this, no doubt, accounts for 

 the somewhat peculiar coast-line on the city side of the Island. High 

 and low lake level periods, which have been known to recur at irregu- 

 lar intervals, also had something to do with the irregularity of the 

 said coast-line. According to the American Engineer's Report, between 

 the years 1825 and 1838, Lake Ontario rose nearly 7 feet and Lake 

 Erie nearly the same, which would change the appearance of the Island 

 very much. But it is not necessary to pursue that phase of the subject 

 further. 



The phenomena of travelling beaches and deposits, similar to the one 

 under consideration, are by no means rare. One, on a small scale, 

 that came under my own observation, and with which many of you 

 may be familiar, occurs near Grimsby, at what is called the lily pond. 

 The cliffs to the east consist of drift clay containing small fragmentary 

 portions of rock entirely unwater-worn. As the cliff becomes under- 

 mined, portions break loose and fall into the water. The clayey por- 

 tions become dissolved, and are carried out to be deposited on the lake 

 bottom, while the fragmentary rocks become water-worn, and are driven 

 westward where they have formed a ridge six or eight feet in height 

 and fifty feet in width across the mouth of the pond, leaving the open- 

 ing at the very western side. 



