An
account was first given of the interesting
personality of Edmund Halley, the son of a prosperous
Winchester Street soap-boiler, and born at his rural
residence at Shoreditch in 1656. The lad was easily
"captain" at St. Paul's School, and at
Oxford contributed papers to the Royal Society while
still in his teens. He perfected the sextant and
diving-bell; first accurately charted stars of the
southern hemisphere; first located the south magnetic
pole; first developed the relation for measuring
heights by the barometer. Above all, by
encouragement, assistance, and accepting all
financial risk, he was responsible for the publishing
of his friend Newton's 'Principia'.
In
connection with this, he undertook the herculean task
of reducing the orbits of the twenty-four comets that
had been best observed. Three of these, seen in 1682
(and charted by himself), 1607, and 1531, he found to
have such similar orbits that he declared them to be
three appearances of the same body, and boldly
prophesied its return in 1758, appealing to
"candid posterity to acknowledge that this was
first discovered by an Englishman." He himself
died in 1742, but the comet was again seen on
Christmas Day, 1758.
Other
comets of recent years were further described in
order to indicate their appearance and probable
nature. The heads consist of clouds of meteoritic
matter, portions of which, dropping behind along
their orbits, produce meteor streams where such
orbits cross that of our earth. The tails are formed
of matter, probably gaseous, but at any rate of
infinitesimal size, and consequently repelled by the
action of the sun's light. Such repulsion occurs with
particles less than the 1/40000 of an inch in
diameter. It is suggestive, for the possible cosmic
universality of life, that the smallest known
life-germs (those of pus) measure only the 1/50000 of
an inch.
[38th
Annual Meeting, Proceedings of the Croydon
Natural History and Scientific Society, 6(5),
cxx-cxxi (1909)]