CHAP. XL.] WENHAM LAKE ICE. 267 



pickerel and perch. Mr. Oakes had recently received a present 

 of a snapping turtle, weighing 25 Ibs., taken from the lake. The 

 ice is conveyed by railway to Boston to be shipped, and the in 

 crease of business has of late been such as to cause the erection 

 of new buildings, measuring 127 feet by 120, and 24 feet high. 

 They stand on the water s edge, by the side of the old store 

 houses, which are very extensive, built of wood, with double 

 walls two feet apart, the space between being filled with saw 

 dust, which excludes the external air ; while tan is heaped up, 

 for the same purpose, on the outside. The work of cutting and 

 storing the ice is carried on in winter, and is not commenced till 

 the ice is at least a foot thick. The surface is always carefully 

 swept and kept free from snow ; and as none but the most com 

 pact and solid ice is fit for the market, it is necessary to shave 

 off three inches or more of the superficial ice, by means of a 

 machine called an ice-plane, drawn by a horse. This operation 

 is especially required after a thaw or a fall of rain, succeeded by a 

 frost, which causes the lake to be covered with opaque, porous ice. 

 Sir Francis Head, in his &quot;Emigrant,&quot; 1846, has attributed 

 the durability of the Wenham Lake ice, or its power of resisting 

 liquefaction, to the intense cold of a North American winter. It 

 is perfectly true that this ice does not melt so fast as English ice ; 

 but the cause of this phenomenon is, I believe, very different from 

 that assigned for it by the late governor of Upper Canada. 

 &quot; People in England/ he says, &quot; are prone to think that ice is 

 ice; but the truth is, that the temperature of 32 Fahrenheit, 

 that at which water freezes, is only the commencement of an 

 operation that is almost infinite ; for after its congelation, water 

 is as competent to continue to receive cold, as it was when it was 

 fluid. The application of cold to a block of ice does not, as in 

 the case of heat applied beneath boiling water, cause what is added 

 at one end to fly out at the other : but, on the contrary, the cen* 

 ter cold is added to and retained by the mass, and thus the tem 

 perature of the ice falls with the temperature of the air, until in 

 Lower Canada it occasionally sinks to 40 below zero, or 72 

 below the temperature of ice just congealed. It is evident, there 

 fore, that if two ice-houses were to be filled, the one with Canada 



