This element will very materially affect
our calculations in such a case as the lower part of the ice in the
Glaciere of the Pre de S. Livres, and the strange suggestive beginning
of a new ice-cave 190 feet below the surface, on the Montagne de l'Eau,
near Annecy. In any open pit or cave, the ordinary atmospheric
influences find such easy access, that the temperature cannot be
expected to follow the law observed when perforations of small bore are
made in the earth, as in the case of the preliminary boring before
commencing to dig a well;[216] but the two glacieres mentioned above are
so completely protected in their lowest parts, that they may be treated
as if they were isolated from external influence of all ordinary kinds;
and it may fairly be said that the mean temperature there ought to be
considerably higher than at the surface.
It is not very likely that the results of the above calculations are
strictly in accordance with what a careful series of observations on the
spot might show. The distance between Geneva and the Glacieres of S.
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