NATURAL HISTORY. 



11 



LAKE CHAMPLAIN PHENOMENA. 



RUPTURE OF ICE. 



NEW YORK BAT. 



ratber from the water than from the atmos- 

 phere, and that the surface of the k^ke, in 

 contact with the atmosphere, after the, ice 

 is all melted, is still warmer than the icy 

 covering was before. 



There is another phenomenon connected 

 with the freezing of Lake Champlain, which 

 is of some interest. At Piouse's Point, where 

 the lake passes into Canada, and where it 

 narrows down into the form of a river and 

 some current is perceptible, it becomes 

 strongly frozen over long before the broad 

 lake closes ; but very soon after the broader 

 and deeper parts of the lake become covered 

 with ice, the ice begins to fail at this place 

 and in a measure disappears, even while 

 the cold is severe and ice is forming in 

 other places. To many, this phenomenon 

 has appeared somewhat mysterious ; but its 

 explanation may, jarobably, be found in the 

 circumstance that the lake at Rouse's Point 

 is quite narrow and shallow and that the 

 water which passes there, before the broad 

 lake freezes, is the surface water and conse- 

 quently the coldest water of the lake. This 

 cold water, passing the Point in a shallow, 

 scarcely perceptible stream, is soon cooled 

 down and congealed at the surface, and 

 the ice usually becomes strong here before 

 the main body of the lake is frozen over. 

 But soon after the broad lake closes over, 

 the ice begins to waste at the Point and 

 usually fails here soon after it becomes 

 good elsewhere. This failure of the ice 

 here, is owing "to the circumstance that, 

 after the lake is covered with ice, the water 

 passing otf here is no longer the cold sur- 

 face water, but the warmer water lying 

 below. It is this warmer water by its mo- 

 tion, though moderate, under the ice and 

 in contact with it, which causes the ice to 

 fiiil here, while it is inci'easing in other 

 places. 



In February, 18-51, there was an occur- 

 rence in Windmill Bay, on the west side 

 of Alburgh, which is worthy of note; the 

 lake and bay being at that time covered 

 with ice. On Saturday, Feb. 15, the wind 

 blew quite hard from the south, and the 

 snow thawed so that water ran in the roads. 

 Saturday evening the wind came suddenly 

 round to the west and blew for a short time 

 with great violence. In the morning of the 

 IGth something unusual was observed in 

 the bay, and on going to it, it was found 

 that the ice had been ruptured for the space 

 of five or six rods each way, and that there 

 were two immense blocks of ice lying upon 

 the firm ice at some distance from the 

 opening made by the rupture. The lar- 

 gest of these blocks was 39^- feet long, 

 with an average width of about 2G feet. 

 The other was thirty-eight feet long and 20 

 wide, and their thickness was 17 inches. 



The nearest of these blocks was 7.^ rods 

 from the opening and they were both the 

 same side up as when they were lying upon 

 the water. The depth of the water at the 

 opening was 17 feet, and the sides of the 

 blocks matched, in part, the margin of the 

 opening. 



Respecting the cause and manner of this 

 occurrence, there were various conjectures ; 

 many supposing that it must have been 

 efiected by the exertion of some sudden force 

 or explosion from beneath. But as a fall 

 from the least elevation must have inevita- 

 bly broken such masses of ice into innume- 

 rable fragments, it is evident that it was 

 not thrown out by a force acting upward, 

 but by a lateral force, which caused the 

 masses to slide iipon the surface of the un- 

 disturbed ice, and to be thus removed from 

 their bed without being broken. The cause 

 of this lateral pressure was probably the 

 wind. While the wind was blowing from 

 the south, a crack might have been opened 

 and these large fragments loosened. Whe|i 

 the wind came round and blew violently 

 from the west, this crack might have closed 

 suddenly and the broken pieces, not re- 

 turning exactly to their former position, 

 miglit have been thrown out with a force 

 sufiicient to cause them to slide to the posi- 

 tion in which they were found, without 

 being broken. 



QUADRUPEDS OF VERMONT. 

 Additional to Part I, Chapter ii. 



To our previous list of IMammalia, we now 

 add two living species, and two extinct fossil 

 species. They are the following : 

 Vcs. noveboracensis, N. Y. Bat. 

 Mus leucopus. White bellied Mouse. 



Eleph. primogeniusl Fossil Elephant. 

 Beluga vermontana. Fossil Whale. 



Besides these, we have made additions to 

 our account, of the following : 



Felis concolor. Panther. 



Phoca veiulina. Seal. 



Sciurus hudsonivs. Red Squirrel. 



,.''*'*?&-.- 



NEW YORK BAT. 



Vespertilio noveboracensis. — Linn. 

 Description. — Hend small ; nose point- 



