ich a rare combination
of moral and intellectual qualities had conspired to render unique.

Amongst the many younger men who were attracted and stimulated by
intercourse with him was Johann Franz Encke. But while Olbers became a
mathematician because he was an astronomer, Encke became an astronomer
because he was a mathematician. A born geometer, he was naturally sent
to Gottingen and placed under the tuition of Gauss. But geometers are
men; and the contagion of patriotic fervour which swept over Germany
after the battle of Leipsic did not spare Gauss's promising pupil. He
took up arms in the Hanseatic Legion, and marched and fought until the
oppressor of his country was safely ensconced behind the ocean-walls of
St. Helena. In the course of his campaigning he met Lindenau, the
militant director of the Seeberg Observatory, and by his influence was
appointed his assistant, and eventually, in 1822, became his successor.
Thence he was promoted in 1825 to Berlin, where he superintended the
building of the new observatory, so actively promoted by Humboldt, and
remained at its head until within some eighteen months of his death in
August, 1865.

On the 26th of November, 1818, Pons of Marseilles discovered a comet,
whose inconspicuous appearance gave little promise of its becoming one
of the most interesting objects in our system. Encke at once took the
calculation of its elements in hand, and brought out the unexpected
result that it revolved round the sun in a period of about 3-1/3
years.[242] He, moreover, detected its identity with comets seen by
Mechain in 1786, by Caroline Herschel in 1795, by Pons, Huth, and
Bouvard in 1805, and after six laborious weeks of research into the
disturbances experienced by it from the planets during the entire
interval since its first ascertained appearance, he fixed May 24, 1822,
as the date of its next return to perihelion. Although on that occasion,
owing to the position of the earth, invisible in the northern
hemisphere, Sir Thomas Brisbane's observatory at Paramatta was
fortunately ready equipped for its recapture, which Ruemker effected
quite close to the spot indicated by Encke's ephemeris.

The importance of this event can be better understood when it is
remembered that it was only the second instance of the recognised return
of a comet (that of Halley's, sixty-three years previously, having, as
already stated, been the first); and that it, moreover, established the
existence of