under pressure at Temperatures below 32° F. 449 
iy form my friend Mr. Willson has suggested to me a possibil- 
, akin to one which I myself had considered, namely that of 
a leverage among the particles, by whic large ocal eer 
ures might be concentrated here and therein the mass. But 
must be remembered that the paint test demonstrates that ther 
can be no speading of moisture from such centers; and a 
further counter-suggestion, Mr. Willson points me to the fact 
that we should, in this way, secure only partial re-union, at 
single points along the faces of fracture in prisms, and only 
local glaciation of the snow at scattered centers, instead of the 
uniform glaciation of the whole mass, which results when the 
pressure is prolonge 
It remains only to lay before the reader such evidence as the 
facts give us of the influence of time upon the processes we ~ 
are discussing. 
I think it will serve our purpose bas “ te point, to intro- 
duce a brief tabular exhibit of quite mber of trials, ar- 
ranged in the order of temperatures ; Sg that an una- 
voidable indallaitencss attaches to the contained results. Those 
pressures which had to be estimated are given within maxi- 
can do is to say, that, at_ particular temperatures, and with cer- 
tain pressures, no more than a certain length of time is required. 
We have only some evidence re garding 1 minimums. ill be 
noticed also that here ice is not considered perfect, unless the 
snowy whiteness has nin ag egree replaced by a 
darker shade, more approaching that of lake ice, and unless | Q 
er 44 
there has been an elimination of the granular structure. 
