Miscellaneous Intelligence. 301 
The general tendency clearly is for the vesicles to become flattened and 
arranged in layers, in planes perpendicular to the direction of the pres- 
sure from without. 
It is clear that the same general tendency must be experienced even 
when there are bubbles of air in the vesicles, although no doubt the re- 
sultant effect would be to some extent influenced by the running down of 
water to the lowest part of each cavity. 
Thelieve it will be found that these principles afford a satisfactory 
se explanation of the origin of that beautiful veined structure which 
f. Forbes has shown to be an essential organic property of glaciers. 
the Névé into ice,”* Prof. Forbes says, “that the conversion into ice is 
simultaneous” (and in a particular case referred to “ identical”) “ with the 
bands ;.... and that these bands are formed where 
© Pressure is most intense, and where the differential motion of the 
: Rd h 
— most complete accordance with the theory indicated above. 
ie in the thirteenth letter, he says, “the blue veins are formed where 
Pressure is most intense and the differential motion of the parts a 
Maximum.” 
Now the theory not only requires pressure, but requires difference of 
ot in different directions to explain the stratification of the vesicles. 
s of pressure in different directions produces the “ differential 
motion Teferred to Professor Forbes. Further, the difference of 
ek in different directions must be continued until 2 very considera- 
amount of this differential motion, or distortion, has taken place, to 
b 
aes ~syper of which the blue veins are induced. Hence also w 
resting ue veins are not forméd in any mass, ever so deep, of snow 
or Corner; * 4: * 
@ 
ghts on Matter and Force, or marvels that encompass us, com- 
by Trosge eom? illustrative of the theory of the earth and the universe ; 
Dp. Teng Ewsanx, author of “ Hydraulics and Mechanics,” &e. 154 
this ltthe vtegd York, 1858—There are many excellent thoughts in 
eaths heat” only effective moving power in a forming earth; that the 
& - Is due to pressure from gravitation; and that gravitation is 
8 of preventing any d e of the mean temperature of a globe 
* Thirteenth Letter on Glaciers, section (2), dated Dec. 1846. 
SERIEs, — No. 90.—MARCH, 1859, 
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