120 
would be of the same natui’e as that produced by elasticity 
in the clamp, but obviously many times as large. If the 
error produced by one thick leather washer be but 10 inches 
of reduced height, surely the effect of the elasticity of the 
clamp will fall well within the limits of error in these expe- 
riments. 
The effect of cold on the breaking of the wire was tried 
thus — the clamp and the lower extremity of the wire were 
cooled by means of ether spray, and the weight dropped as 
before. The effect of cooling the wire near the clamp was 
in all cases to make the wire break more easily, in some 
cases very markedly so. A similar result would follow 
under similar circumstances from the formula for the 
resilience i-g- ; and it is the almost universal experience 
of those who have to handle crane chains and lifting tackle 
that these are most liable to breakage in cold weather. To 
this efiect of temperature and to the variable quality of 
wire even in the same coil I attribute the discrepancy 
between the various observations. 
The first column gives the height of fall observed, the 
second the reduced height, and the third the point at which 
the wire broke. The observations marked * are those in 
which cold was applied. The two series were tried on 
different days about a fortnight apart and on ware from 
different parts of the same coil. In all cases the upper 
clamp rested on the bare boards of the floor above. 
FIRST SERIES. 
161 bs. weight. 
Inches. 
Inches. 
Point of Rupture. 
72 .... 
GO 
78 .... 
65 
78 .... 
65 
81 .... 
67£ 
82 .... 
08£ 
.... 21" from top. 
84 .... 
70 
84 .... 
70 
*48 .... 
40 
*54 .... 
45 
*60 .... 
50 
*72 .... 
60 
