h cement a straight
and even Cylindrical pipe of Glass, EFGH, the Diameter of whose cavity let
be exactly one tenth of the Diameter of the greater Cylinder. Let this pipe
be mark'd at GH with a Diamant, so that G from E may be distant just two
inches, or the same height with that of the cavity of the greater Cylinder,
then divide the length EG exactly into 10 parts, so the capacity of the
hollow of each of these divisions will be 1/1000 part of the capacity of
the greater Cylinder. This vessel being thus prepared, the way of marking
and graduating the _Thermometers_ may be very easily thus performed:

Fill this Cylindrical vessel with the same liquor wherewith the
_Thermometers_ are fill'd, then place both it and the _Thermometer_ you are
to _graduate_, in water that is ready to be frozen, and bring the surface
of the liquor in the _Thermometer_ to the first marke or [0]; then so
proportion the liquor in the Cylindrical vessel, that the surface of it may
just be at the lower end of the small glass-Cylinder; then very gently and
gradually warm the water in which both the _Thermometer_ and this
Cylindrical vessel stand, and as you perceive the ting'd liquor to rise in
both stems, with the point of a Diamond give several marks on the stem of
the _Thermometer_ at those places, which by comparing the expansion in both
Stems, are found to correspond to the divisions of the cylindrical vessel,
and having by this means marked some few of these divisions on the Stem, it
will be very easie by these to mark all the rest of the Stem, and
accordingly to assign to every division a proper character.

A _Thermometer_, thus marked and prepared, will be the fittest Instrument
to make a Standard of heat and cold that can be imagined. For being sealed
up, it is not at all subject to variation or wasting, nor is it liable to
be changed by the varying pressure of the Air, which all other kind of
_Thermometers_ that are open to the Air are liable to. But to proceed.

This property of Expansion with Heat, and Contraction with Cold, is not
peculiar to Liquors only, but to all kind of solid Bodies also, especially
Metals, which will more manifestly appear by this Experiment.

Take the Barrel of a Stopcock of Brass, and let the Key, which is well
fitted to it, be riveted into it, so that it may slip, and be easily turned
round, then heat this Cock in the fire, and you will find the Key so
swollen, that you will not be able to turn it round in th