which operate continually at the bottom of the sea offers points of
interest which well repay the labor of the geologist. He finds there,
indeed, a precious field to be compared with stratified deposits; for
in spite of the enormous depth to which they form a part of continents,
they are of analogous origin. Delesse laboriously studied the products
of the innumerable soundings taken in most of the seas. He arranged the
results in a work which has become classical with the beautiful atlas of
submarine drawings which accompany it. Though he never slackened in his
own especial work, he made much of the work of others. The "Revue des
Progres de la Geologie," with which he enriched the "Annales des Mines"
for twenty years, would have been sufficient to engross the time of a
less active scientific man, and one less ready to grasp the opening of a
discovery. This indefatigable theorist never neglected the applications
of science: the nature and the changes of the layers which form the
under earth; the course and the depth of the subterraneous sheets of
water; the mineralogical composition of the earth's vegetation, were
represented by him on several charts and plans drawn out in proper form.
His maps which follow the route of many of the great French lines of
railway explain the kind of soil upon which they are laid, and are of
daily use. In the pursuit of his numerous scientific works, Delesse
never failed in discharging his duties in the Corps des Mines. Having
in 1864 quitted the service of the Government of Paris, which he had
occupied for eighteen years, he was made professor of agriculture, of
drainage, and irrigation, at the School of Mines, where he established
instruction in these before being called to found the course of geology
at the Agricultural Institution. Promoted to be Inspector-General of
Mines in 1878, and charged with the division of the south east of
France, he preserved to the end of his life these new duties, for which,
to the regret of the School of Mines, he gave up his excellent lessons
there. During the year of 1870 Delesse fulfilled his duties as a