54 A PEEP AT 



all around, the space between which is filled with 

 saw-dust, thus interposing a medium that is a non- 

 conductor of heat between the ice and the external 

 air; the consequence of which is, that the ice is 

 entirely unaffected by any condition or temperature 

 -of the external atmosphere, and can be preserved 

 \without waste for any indefinite time. 



^* The machinery employed for cutting the ice is 

 very curious, and is worked by men and horses, in the 

 following manner : From the time when the ice first 

 forms, it is carefully kept free from snow until it is 

 thick enough to cut ; that process commences when 

 the ice is a foot thick. A surface of some two acres 

 is then selected, which, at that thickness, will furnish 

 about two thousand tons ; and a straight line is drawn 

 through its centre from side to side each way. A 

 small hand-plough is pushed along one of those lines, 

 until the groove is about three inches deep, and a 

 quarter of an inch in width, when the ' marker ' is 

 introduced. This instrument is drawn by two horses, 

 and makes two new grooves, parallel with the first, 

 from twenty to forty inches apart, the gauge remain- 

 ing in the original groove. The marker is then 

 shifted to the outside groove, and makes two more. 

 Having drawn these lines over the whole surface in 



