264 Scientific Intelligence. 
which ice changes its form through fracture and regelation. In 
Mr. Mathew’s first experiment, conducted during a thaw, a thick 
plank of ice supported at each end was deflected at the middle 
through a space of 7 inches in as many hours. Although none 
ut very minute fissures were observed, the facts did not seem to 
me altogether inconsistent with that explanation. In the second 
series of observations, made during the severe frost of Februa 
last, Mr. Mathews found that at temperatures notably below the 
freezing-point a _ of ice, supported as before, subsides slowly 
the researches of M. Tresca, we are led to admit that ice, in com- 
m rent] rigid 
tain degree of plasticity which is exhibited by changes of form 
effected very slowly under the action of forces of moderate amount, 
Ww 
able researches of Professor Tyndall. Whatever may be the final 
—. of men of science, I feel quite sure that it will not con- 
rm the opinion expressed by Canon Moseley in his latest publica- 
ss that “the phenomena of glacier-motion belong rather to 
mechanical philosophy than to physics.” Every real advance that 
has been made t oward the explanation of those phenomena has 
such additional acquaintance with those Les spin as may be de- 
rived from continued observation and experim 
The North American Lak ea cuneciorédc vm ‘Chronometers of 
Post-glacial time; by Dr. Epmunp ANDREWs. 24 pp. roy. 8vo. 
(Trans. Acad. Sci. Chicago, vol. 1 ie ee sr le in 
the areas - the =a beaches, the or these beaches hav e 
nd 
the sel sand moved in the rocess; and from the elements 
thus obtained, arrives at the ari conclusions : 
(1.) The upper beach began to form riba foPabane cae - 
: erin 
where they remained till a thin bed o peat accreted on the sti 
slope vacated by the waves. I have not been able to collect data 
for a calculation of this first low-water period, but from the posi- 
* In Dana’s 3 Manmal of, Gookgy, lien ee Sr ong the 
means of mo! the ground of obse similar to the above, Tinie by 
Kane in his WAR Ageia Seshestonn” 
