THE 
LONDON, EDINBURGH ano DUBLIN 
PHILOSOPHICAL MAGAZINE 
AND 
JOURNAL OF SCIENCE. 
[FOURTH SERIES.} 
OCTOBER 1857. 
XXIX. Observations on the Structure of Glacier Ice. 
By T. H. Huxtey, F.R.S. &c. 
The Government School of Mines, 
My pDEAR TYNDALL, Jermyn Street, September 14, 1857. 
N the following pages I have given you some account of the 
experiments and observations upon the structure of glacier 
ice, which, at your suggestion, I commenced during our sojourn 
at the Montanvert this autumn. No one knows better than 
yourself how much these subjects grow under the hands of the 
inquirer, and how little claim my brief investigations have to the 
character of completeness. Nevertheless my conclusions, so far 
as they go, are based on such clear and decisive evidence, and 
are so totally opposed to the views entertained by the highest 
authorities, that I feel I shall be doing more good by publishing 
than by withholding them. 
I will in the first place state what I have myself observed 
with regard to the structure and the permeability of glacier ice, 
and afterwards I will compare my results with those which have 
been arrived at by others. 
Structure of Glacier Ice.—A mass of ice freshly extracted from 
any part of the Mer de Glace, the Glacier du Géant, or the 
glacier of La Brenva, at a depth of 8 or 10 inches from the sur- 
face, always presented the following characters when examined 
either with the naked eye, or with a lens of a magnifying power 
of thirty or forty diameters. 
It broke with a vitreous fracture; and when the surface was 
made even, either with a sharp knife, or by rubbing on a warm sur- 
face, it appeared perfectly smooth and glassy, exhibiting not the 
Phil. Mag. S. 4. Vol. 14. No. 93. Oct. 1857. R 
