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AMERICAN JOURNAL OF SCIENCE, 
[THIRD SERIES] 
Art. XLIV.—EZlasticity of Ice; by JoHN TROWBRIDGE and 
Austin L. McRag. 
APPARENTLY the only previous experiments made to deter- 
mine the modulus of elasticity of ice are those of Benjamin 
Bevan.* He went to a pond where the ice was about ten 
centimeters thick and sawed one end and two sides of a beam, 
eaving the other end attached to the main body of ice, He 
then loaded the free end and obtained the absolute modulus 
54X10°. Nothing is said about the ice returning to its first 
position when the load was removed, nor of the deflection due to 
the weight of the beam itself. As the weight of the beam was 
four or five times the heaviest weight used, this deflection would 
be quite appreciable. The lower surface of the ice apparently 
rested on the water of the pond which prevented it from deflect- 
ing as far as it would have done. The upward pressure of the 
yess would in part counterbalance the effect of the weight’of 
€ beam. 
Methods of Observation. 
We first endeavored to obtain the modulus by a direct pull 
ona bar. For this purpose water was put in brass tubes cl 
at one end and boiled so as to expel bubbles of air, then frozen, 
sometimes artificially, but generally by placing the tubes out 
of the window and allowing the water to freeze naturally. The 
* Phil. Trans., 1826. 
Am. Jour, Sct.—Tuirp Series, Vou. XXIX, No. 173.—May, 1885. 
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