222 On Water and Air . [May 
appearing after the change as solid and as homogeneous as 
before. , 
A curious phenomenon was first observed by baraday, 
who found that when two pieces of ice with moistened sur- 
faces were placed in contact, they became cemented together 
by the freezing of a film of water between them. . I have 
here two slabs of ice, the surfaces of which I will press 
together, and you see I have frozen the two slabs into one 
mass. Prof. Bottomley made an experiment recently which 
bears upon the subject. It is there in aftion before you. 
Upon the two uprights (Fig. 32) is placed a large block of 
clear ice (a b) with a loop of wire round it : twelve hours 
Fig. 32. 
ago a 28 lbs. weight was attached to the wire. The wire 
immediately commenced to enter the ice, and you. see by 
this time it has passed half-way through it, but the ice has 
remained undivided : except for a little opacity along the 
plane of passage, it shows no signs of ever having been 
divided. If we allow it to go on it will pass right through 
the ice, the severed surfaces re-freezing, and leaving the 
block entire as at the commencement. 
I have here a number of moulds of different shapes, and 
if time permitted I could have shown you that by filling 
them with fragments of ice, and subjecting the ice to 
pressure, I could have moulded these fragments into cups, 
spheres, vases, &c., of solid ice ; so by these illustrations 
you can readily understand how a substance which so readily 
