PUNCH'S INFORMATION FOR THE PEOPLE.--No. 2.

THE THERMOMETER.


_General Description_.--The thermometer is an instrument for showing the
_temperature_; for by it we can either see how fast a man's blood boils
when he is in a passion, or, according as the seasons have occurred this
year, how cold it is in summer, and how hot in winter. It is mostly cased
in tin, all the brass being used up by certain lecturers, who are faced
with the latter metal. It has also a glass tube, with a bulb at the end,
exactly like a tobacco-pipe, with the bowl closed up; except that, instead
of tobacco, they put mercury into it. As the heat increases, the mercury
expands, precisely as the smoke would in a pipe, if it were confined to the
tube. A register is placed behind the tube, crossed by a series of
horizontal lines, the whole resembling a wooden milk-score when the
customer is several weeks in arrear.

_Derivation of Name_.--The thermometer derives its name from two Greek
words, signifying "measure of heat;" a designation which has caused much
warm discussion, for the instrument is also employed to tell when it
freezes, by those persons who are too scientific to find out by the tips of
their fingers and the blueness of their noses.

_History and Literature of the Thermometer_.--The origin of the instrument
is involved in a depth of obscurity considerably below _zero_; Pliny
mentions its use by a celebrated brewer of Boeotia; we have succeeded,
after several years' painful research, in tracing the invention of the
instrument to Mercury, who, being the god of thieves, very likely stole it