6 ROYAL SUCIKTY OF CANAUA 



essarily Cdinjaratively shallow, and are the unly places, after all other 

 water is frozen over, \vhere " anchored " ice is formed and found. This 

 differs from lake ice in that the latter melts where it freezes, while 

 anchor ice, when compelled by milder weather to let go its hold upon 

 the bottom, rises, and is immediately drawn under the fixed ice below, 

 and does not dissolve until the river breaks up in the spring. The latent 

 heat of water, disengaged in. freezing, — which ]irocess occurs so fre- 

 quently during the five months of winter, — is imparted to the atmos- 

 phere, but is not again absorbed by melting ice, as would be the case in 

 lakes, or in deep sluggish rivers. 



AgaiH, radiation is supposed to play an important part in " anchor- 

 ing " the floating particles of ice to the river bottom, which is said to 

 be cooled so rapidly by the ice laden current above it as to become frozen, 

 and then begin to attract the passing ice needles, and fix them to its 

 bed. 



If mother earth, in mid-winter, contributes any of her impounded 

 heat to the outer atmosphere, thes3 almost innumerable unfrozen spaces 

 certainly offer great facilities for giving vent to her suppressed emotions. 



WATER POWER. 



From the Straits of Belle Isle to Montreal, and thence ascending 

 the Ottawa, the tributaries of the St. Lawrence and of the Ottawa des- 

 cend, through the Laurcntian region, from elevations of 1,800 to 1,000 

 ieet above tide, and débouche within a few miles of each other except 

 immediately about the Saguenay. In many cases they bring their prin- 

 cipal cataracts very near their outfall, notably in the case of the famous 

 Falls of Montmorency, which, leaping directly into the St. Lawrence 

 from a height of 250 feet, are utilized to light the streets and drive the 

 tram cars of Quebec. 



Somewhat similar conditions exist on the south shore of the St. 

 Lawrence until the liiehelieu river (the outlet of Lake Champlain) is 

 reached, where at Chambly, water power is about to be used to send the 

 electric current into Montreal in competition with steam and a similar 

 water power from the Lachine liapids. 



The divide between the St. Lawrence and the Ottawa is studded with 

 lakes, west of the Rideau Canal, a principal outlet for which, — on the 

 soutii, — is the liiver Trent, discharging into the Bay of Quinte, with 

 large mills and much undeveloped water power at its mouth : and on 

 the north, some half a dozen important tributaries discharging into the 

 Ottawa. 



