(631.) 
(632.) 
Thomson, 
Count of 
Rumford. 
(633.) 
His early 
history 
and studies. 
(634.) 
Enquiries 
into the 
economical 
applica- 
tions of 
heat. 
940 MATHEMATICAL AND PHYSICAL SCIENCE. [Diss. VI. 
sidering the novelty of the experiment in 1804 (only 
twenty-one years after Montgolfier’s first successful 
experiment), this fact speaks strongly for his courage 
and zeal. These ascents were also the first undertaken 
with strictly scientific aims, and the observations made 
were highly interesting in ‘connection with the decre- 
ment of temperature in the atmosphere, with the uni- 
formity of composition of air at all heights, and with 
the question of whether the magnetic force of the 
earth diminishes at such elevations. This last en- 
quiry was not conclusively answered. 
With M, de Humboldt he made observations on 
terrestrial magnetism in Italy, and on other subjects. Miscella- 
By desire of Laplace he studied the facts of capillary neous ex- 
attraction. In more immediate connection with the Peuments 
subject of the present chapter, he made some valu- Suse, 
able experiments on hygrometry, on the mechanical 
properties of vapour of different kinds, and on the 
specific heat of the gases, His fame, however, mainly 
rests on the two investigations to which we previously 
referred, and on the results of his balloon journey. 
His later years were devoted to practical enquiries 
connected with chemistry, and to his official duties at 
the Mint. He died at Paris on the 9th May 1850. His death. 
§ 4. RuMFORD.—Economical applications of Heat.—Point of Maximum Density of Water ; Hope. 
—Friction as a source of Heat. Theory that Heat is convertible into Mechanical Energy ; 
Mr Joule. 
Tue name of Thomson, Count of Rumford, de- 
serves a passing notice in the history of the physi- 
eal sciences, if not for the absolute importance of 
his discoveries, at least as an instance of a class of 
benefactors to mankind at once in a physical and in- 
tellectual point of view. He was altogether in ad- 
vance of his age in the application of correct theory 
to the improvement of the social condition of the 
lowest classes; and many of his experiments, and, 
indeed, discoveries, seem now at once so simple and 
so familiar, that we are apt to forget how entirely 
original they were sixty years since. 
Sir Bensamin Tuomson, an American by birth, a 
British knight, and a Bavarian or rather Austrian 
count, was born in the United States in 1753, and 
passed his earlier years almost entirely at military 
stations during the American war, being engaged 
on the British side. After the establishment of in- 
dependence, he quitted his country for ever; came 
first to England, where he was well received, and 
proposing to enter the Austrian service, he proceeded 
as far as Munich, where, having become known to 
the elector of Bavaria, he was induced to settle; 
and having received different civil and military ap- 
pointments, he devoted himself for a series of years 
to the improvement of the social condition of that 
capital. He introduced great improvements into the 
management of the army; the mechanical and chemi- 
cal departments of the artillery had a peculiar charm 
for him; they were conducted on strictly scientific 
principles, and, in return, were made to contribute 
important results to science, His experiments on the 
heat of friction, deduced from the boring of cannon, 
are amongst the best we possess; and they led him 
to results of considerable theoretical importance to 
which I shall presently refer. 
But his most serviceable effortson behalf of man- 
kind were in the treatment of the mendicant classes 
with which Munich then swarmed. Salutary views 
of the importance of industry, order, morality, and 
public economy, were most happily united to a 
happy versatility of talent in physical research, to 
unwearied patience and great liberality, in effecting 
one of the greatest social reforms on record. The 
strict statistics of a great house of industry were 
ascertained with reference to the most seemingly in- 
significant details, and, in particular, all the appli- 
cations of Heat to the physical wants of mankind 
were studied with equal assiduity and success. The 
warmth of clothing was traced to the amount of still 
air entangled amongst its fibres,—the dissipation of 
heat, whether from a thermometer or a kitchen boiler, 
was classified under radiation, conduction, and con- 
vection, the last and often most important of which 
(signifying the influence of currents in liquids and 
gases in conveying heat by the changing density of 
their parts) had hardly before been recognised, or at 
least made the subject of formal experiment,—the 
effective heat due to the combustion of different kinds 
of fuel, tested by a calorimeter of his own invention, 
—the economy of light based on an investigation of 
the properties of flame ;—these were but a few of 
the trains of enquiry, of which his Mendicity House 
was the primary object. Charity and science went Practical 
hand in hand; and when we award to Watt the benefits re- 
highest honours for an invention which enabled him wting. 
to create mechanical force at an economy of two- 
thirds of the coal previously consumed, shall we 
deny Rumford a civic crown for having so improved 
the methods of heating apartments and of cooking 
food, as to produce a saving in the precious element 
of heat, varying from one-half to seven-eighths of the 
fuel previously consumed ?!_ When we consider the 
enormous price of wood in nearly every part of the 
Continent, the destruction of forests which has oc- 
curred, and the consequent injury to the climate, as 
1 In the hospital of Verona he reduced the consumption of wood to one-eighth. Some one wittily said of Rumford, that he 
would not rest until he had cooked his dinner with his neighbour’s smoke. 
edd 
