_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
from somebody else. Of ancient writers, there are few except Hannibal (who
used it on crossing the Alps) and Julius Cæsar, that notice it. Bacon
treats of the instrument in his "Novum Organum;" from which Newton cabbaged
his ideas in his "Principia," in the most unprincipled manner. The
thermometer remained stationary till the time of Robinson Crusoe, who
clearly suggested, if he did not invent the register, now universally
adopted, which so nearly resembles his mode of measuring time by means of
notched sticks. Fahrenheit next took it in hand, and because his
calculations were founded on a mistake, his scale is always adopted in
England. Raumur altered the system, and instead of giving the thermometer
mercury, administered to it 'cold without,' or spirits of wine diluted with
water. Celsius followed, and advised a medium fluid, so that his
thermometer is known as the centigrade. De Lisle made such important
improvements, that they have never been attended to; and Mr. Sex's
differential thermometer has given rise to considerably more than a
half-dozen different opinions. All these persons have written learnedly on
the subject, blowing respectively hot or cold, as their tastes vary. The
most recent work is that by Professor Thompson--a splendid octavo,
hot-pressed, and just warm from the printer's. Though this writer disagrees
with Raumur's temperance principles, and uses the strongest spirit he can
get, instead of mercury, we are assured that he is no relation whatever to
Messrs. Thompson and Fearon of Holborn-hill.
_Concluding Remarks and Description of Punch's Thermometer_.--It must be
candidly acknowledged by every unprejudiced mind, that the thermometer
question has been most shamefully handled by the scientific world. It is
made an exclusive matter; they keep it all to themselves; they talk about
Fahren_heit_ with the utmost coolness; of Raumur in un-understandable
jargon, and fire whole volleys of words concerning the centigrade scale,
till one's head spins round with their inexplicable dissertations. What is
the use of these interminable technicalities to the world at large? Do they
enlighten the rheumatic as to how many coats they may put on, for the
Midsummer days of this variable climate? Do their barometers tell us when
to take an umbrella, or when to leave it at home? No. Who, we further ask,
knows _how_ hot it is when the mercury stands at 120°, or how cold it is
when opposite 32° of Fahrenheit? Only the initiated, a class of persons
that can generally stand fire like salamanders, or make themselves
comfortable in an ice-house.
Deeply impressed with the importance of the subject, PUNCH has invented a
new thermometer, which _may_ be understood by the "people" whom he
addresses--the unlearned in caloric--the ignorant of the principles of
expansion and dilatation. Everybody can tell, without a thermometer, if it
be a coat colder or a cotton waistcoat warmer than usual when he is _out_.
But at home! Ah, there's the rub! There it has been impossible to ascertain
how to face the storm, or to turn one's back upon the sunshine, till
to-day. PUNCH'S thermometer decides the question, and here we give a
diagram of it. Owing a stern and solemn duty to the public, PUNCH has
indignantly spurned the offers of the British Association to join in their
mummeries at Plymouth--to appear at their dinners for the debasement of
science. No; here in his own pages, and in them only, doth he propound his
invention. But he is not exclusive; having published his wonderful
invention, he invites the makers to copy his plan. Mr. Murphy is already
busily arranging his Almanac for 1842, by means of a PUNCH thermometer,
made by Carey and Co.