ion for the mechanical arts and scientific studies. He
attended the lectures of J. A. C. Charles, L. N. Vaquelin and J. B.
Leroy, and exhibited before the Academy of Science an hydraulic machine
of his own invention of which the model was the subject of a flattering
report, and was placed in Charles's collection. The events of the
Revolution soon gave him an opportunity for a further display of his
inventive faculty. The war with England deprived France of plumbago; he
substituted for it an artificial substance obtained from a mixture of
graphite and clay, and took out a patent in 1795 for the form of pencil
which still bears his name. At this time he was associated with Monge
and Berthollet in experiments in connexion with the inflation of
military balloons, was conducting the school for that department of the
engineer corps at Meudon, was perfecting the methods of producing
hydrogen in quantity, and was appointed (1796) by the Directory to the
command of all the aerostatic establishments. He was at the head of the
newly created Conservatoire des arts et metiers, and occupied himself
with experiments in new compositions of permanent colours, and in 1798
constructed a metal-covered barometer for measuring comparative heights,
by observing the weight of mercury issuing from the tube. Summoned by
Bonaparte to take part as chief of the aerostatic corps in the
expedition to Egypt, he considerably extended his field of activity, and
for three years and a half was, to quote Berthollet, "the soul of the
colony." The disaster of Aboukir and the revolt of Cairo had caused the
loss of the greater part of the instruments and munitions taken out by
the French. Conte, who, as Monge says, "had every science in his head
and every art in his hands," and whom the First Consul described as
"good at everything," seemed to be everywhere at once and triumphed over
apparently insurmountable difficulties. He made, in an almost
uncivilized country, utensils, tools and machinery of every sort from
simple windmills to stamps for minting coin. Thanks to his activity and
genius, the expedition was provided with bread, cloth, arms and
munitions of war; the engineers with the exact tools of their trade; the
surgeons with operating instruments. He made the designs, built the
models, organized and supervised the manufacture, and seemed to be able
to invent immediately anything required. On his return to France in 1802
he was commissioned by the minister