394 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 8, 



does not prevent the formation of ground-ice ; for it is seen abun- 

 dantly on the bottom of the St. -Lawrence Eapids, and at the Tubular 

 Bridge, Montreal, which affords a favourable point for observation, 

 before the surface is frozen over. As the frost continues, the ice at 

 the bottom thickens. It is tubular, or honeycombed, in the direc- 

 tion of the current ; and the water pours through the tubes. It ia 

 rarely solid, but is so after long continuance of hard frost. It 

 adheres to the stones at the bottom, or to the ground itself, and it 

 remains anchored until its power of flotation enables it to rise to the 

 surface and carry its anchor with it. It comes to the surface with 

 stones attached to it. These stones, of course, bear a proportion to 

 the mass of ice. When the mass is small, the stones it raises are 

 small, and are only pebbles ; but when the mass is large) and it is 

 often a large mass that rises to the surface) it brings adherent to it 

 large stones, deserving to be called small boulders. The mass floats 

 away down the stream to the next part of the river that is frozen 

 over at the surface. There it becomes frozen in with the mass of 

 surface-ice, and in a very few hours loses its porous condition alto- 

 gether." Such is the valuable testimony of a close observer in these 

 matters, showing how this powerful agent is now acting from year 

 to year in producing such changes on the surface of the earth as 

 those of Crab Island adduced in my former paper, and Tidlar's 

 Island in the present one. Dr. Landor also speaks of having seen 

 in the small rivers that form the Canadian river Thames " a vast 

 number of pebbles and stones, as big as a foot in diameter, carried 

 away by ground-ice," and also of observing " the ice rise with 

 stones attached." I might add to what has been already advanced 

 from this valuable essay on this head ; but I trust that at some sub- 

 sequent period the author may lay the results of his observations 

 on these matters before the Geological Society ; for I believe them 

 well worthy of its attention. 



A visit just made (at the time I write) to the locality of Fidlar's 

 Island reveals a rapid, surging up with white foam, and the water 

 thus bounding over its site, whilst between it and Flat Creek Island, 

 about 200 yards lower down the stream, a new shoal has been 

 formed, probably by a portion of the deh'is of the former island. 

 A mile lower down the river is Patrick's Island, which furnishes 

 evidence that the same causes are operating extensively there, as 

 it is greatly reduced in size, and glacial action has almost de- 

 prived its surface of soil — two detached groups of trees being all that 

 now remains of it. Before long a shoal or a rapid will be all that 

 remains to mark the site of Patrick's Island. 



Another remarkable example of glacial action in Canada is the 

 removal of Salmon Island, the history of which has but recently 

 come under my notice. At the junction of the Bay of Quinte 

 with Lake Ontario there is an island of some magnitude and well 

 settled with inhabitants, formerly named Isle de Jonti by the 

 early French explorers, from Chevalier de Jonti, an associate of the 

 enterprising explorer La Salle, but now known as Amherst Island. 

 Off the eastern extremity of this island there was formerly a small 



