f the glass of the bottle has undergone no permanent deformation, the
level will rise exactly to the zero mark, and denote that the bottle
has supported the test without any modification of its structure. But
if, on the contrary, the level does not return to the zero mark, the
limit of the glass's elasticity has been extended, its molecules have
taken on a new state of equilibrium, and its resistance has
diminished, and, even if it has not broken, it is absolutely certain
that it has lost its former resistance and that it presents no
particular guarantee of strength.

The vessel, A B, which must be always full of water, is designed to
keep the bottle at a constant temperature during the course of the
experiment. This is an essential condition, since the bottle thus
filled with water constitutes a genuine thermometer, of which _a b_ is
the graduated tube. It is therefore necessary to avoid attributing a
variation in level due to an expansion of the water produced by a
change in temperature, to a deformation of the bottle.

The test, then, that can be made with bottles by means of the
elasticimeter consists in compressing them to a pressure of ten
atmospheres when filled with water at a temperature of 25 deg., and in
finding out whether, under such a stress, they change their volume
permanently. In order that the elasticimeter may not be complicated by
a special heating apparatus, it suffices to determine once for all
what the pressure is that, at a mean temperature of 15 deg., acts upon
bottles with the same energy as that of ten atmospheres at 25 deg..
Experiment has demonstrated that such stress corresponds to twelve
atmospheres in a space in which the temperature remains about 15 deg..

In addition, the elasticimeter is capable of giving other and no less
useful data. It permits of comparing the resistance of bottles and of
classifying them according to the degree of such resistance. After
numerous experiments, it has been found that first class bottles
easily support a pressure of twelve atmospheres without distortion,
while in those of an inferior quality the resistance is very variable.
The champagne wine industry should therefore use the former
exclusively.

Various precautions must be taken in the use of corks. The bottles
that lose their wine in consequence of the bad quality of their corks
are many in number, and it is not long since that they were the cause
of genuine disaster to the champagne trade.

Mr