A system of this kind must not be looked upon as a simple _jeu d'esprit_, since this very practicable experiment would easily permit us to check, with a precision which could be carried very far, the constancy of an interval of time.
From the practical point of view, chronometry has made in these last few years very sensible progress.

The errors in the movements of chronometers are corrected in a much more systematic way than formerly, and certain inventions have enabled important improvements to be effected in the construction of these instruments.

Thus the curious properties which steel combined with nickel--so admirably studied by M.Ch.Ed.

Guillaume--exhibits in the matter of dilatation are now utilized so as to almost completely annihilate the influence of variations of temperature.
Sec.5.THE MEASURE OF TEMPERATURE From the three mechanical units we derive secondary units; as, for instance, the unit of work or mechanical energy.

The kinetic theory takes temperature, as well as heat itself, to be a quantity of energy, and thus seems to connect this notion with the magnitudes of mechanics.