HERSCHEL.

_From an Original Picture in the Possession of_ WM. WATSON, M.D.,
F.R.S.]

In 1783, Herschel married an estimable lady who sympathized with his
pursuits. She was the only daughter of a City magnate, so his pecuniary
difficulties, such as they were (they were never very troublesome to
him), came to an end. They moved now into a more commodious house at
Slough. Their one son, afterwards the famous Sir John Herschel, was
born some nine years later. But the marriage was rather a blow to his
devoted sister: henceforth she lived in lodgings, and went over at
night-time to help him observe. For it must be remarked that this family
literally turned night into day. Whatever sleep they got was in the
day-time. Every fine night without exception was spent in observing: and
the quite incredible fierceness of the pursuit is illustrated, as
strongly as it can be, by the following sentence out of Caroline's
diary, at the time of the move from Datchet to Slough: "The last night
at Datchet was spent in sweeping till daylight, and by the next evening
the telescope stood ready for observation at Slough."

Caroline was now often allowed to sweep with a small telescope on her
own account. In this way she picked up a good many nebulae in the course
of her life, and eight comets, four of which were quite new, and one of
which, known since as Encke's comet, has become very famous.

The work they got through between them is something astonishing. He made
with his own hands 430 parabolic mirrors for reflecting telescopes,
besides a great number of complete instruments. He was forty-two when he
began contributing to the Royal Society; yet before he died he had sent
them sixty-nine long and elaborate treatises. One of these memoirs is a
catalogue of 1000 nebulae. Fifteen years after he sends in another 1000;
and some years later another 500. He also discovered 806 double stars,
which he proved were really corrected from the fact that they revolved
round each other (p. 309). He lived to see some of them perform half a
revolution. For him the stars were not fixed: they moved slowly among
themselves. He detected their proper motions. He passed the whole
northern firmament in review four distinct times; counted the stars in
3,400 gauge-fields, and estimated the brightness of hundreds of stars.
He also measured as accurately as he could their proper motions,
devising for this purpose the method which still to this day remains in
use.