s occurred to him. Although not
made public until 1797, "Olbers's method" was then universally adopted,
and is still regarded as the most expeditious and convenient in cases
where absolute rigour is not required. By its introduction, not only
many a toilsome and thankless hour was spared, but workers were
multiplied, and encouraged in the prosecution of labours more useful
than attractive.

The career of Heinrich Olbers is a brilliant example of what may be done
by an amateur in astronomy. He at no time did regular work in an
observatory; he was never the possessor of a transit or any other fixed
instrument; moreover, all the best years of his life were absorbed in
the assiduous exercise of a toilsome profession. Born in 1758 at the
village of Arbergen, where his father was pastor, he settled in 1781 as
a physician in the neighbouring town of Bremen, and continued in active
practice there for over forty years. It was thus only the hours which
his robust constitution enabled him to spare from sleep that were
available for his intellectual pleasures. Yet his recreation was, as Von
Zach remarked,[241] no less prolific of useful results than the severest
work of other men. The upper part of his house in the Sandgasse was
fitted up with such instruments and appliances as restrictions of space
permitted, and there, night after night during half a century and
upwards, he discovered, calculated, or observed the cometary visitants
of northern skies. Almost as effective in promoting the interests of
science as the valuable work actually done by him, was the influence of
his genial personality. He engaged confidence by his ready and
discerning sympathy; he inspired affection by his benevolent
disinterestedness; he quickened thought and awakened zeal by the
suggestions of a lively and inventive spirit, animated with the warmest
enthusiasm for the advancement of knowledge. Nearly every astronomer in
Germany enjoyed the benefits of a frequently active correspondence with
him, and his communications to the scientific periodicals of the time
were numerous and striking. The motive power of his mind was thus widely
felt and continually in action. Nor did it wholly cease to be exerted
even when the advance of age and the progress of infirmity rendered him
incapable of active occupation. He was, in fact, _alive_ even to the
last day of his long life of eighty-one years; and his death, which
occurred March 2, 1840, left vacant a position wh