rous attack Sir William recovered, but thenceforth it
was clear to his friends that his strength gradually decreased, though
not his enthusiasm or his industry. He persevered in his life-long
labours with all his old intellectual force. What failed him was neither
his tender affections nor his mental powers; but his body refused to
answer all the demands made upon it by the resolute will,--the sword was
slowly but surely wearing out the scabbard. Under the date of April 2,
1819, we meet with an ominous entry in his loving and faithful sister's
diary:--

"My brother left Slough, accompanied by Lady Herschel, for
Bath, he being very unwell; and the constant complaint of
giddiness in the head so much increased, that they were obliged
to be four nights on the road both going and coming. The last
moments before he stepped into the carriage were spent in
walking with me through his library and workrooms, pointing
with anxious looks to every shelf and drawer, desiring me to
examine all, and to make memorandums of them as well as I
could. He was hardly able to support himself; and his spirits
were so low, that I found difficulty in commanding my voice so
far as to give him the assurance he should find on his return
that my time had not been misspent.

"When I was left alone, I found that I had no easy task to
perform, for there were packets of writings to be examined
which had not been looked at for the last forty years. But I
did not pass a single day without working in the library as
long as I could read a letter without candlelight, and taking
with me papers to copy, which employed me for best part of the
night; and thus I was enabled to give my brother a clear
account of what had been done at his return. But (May 1) he
returned home much worse than he went, and for several days
hardly noticed my handiwork."

To this same year of decay and decline (1819) belongs a small slip of
yellow paper, inscribed with the following lines in a tremulous and
feeble handwriting, which is jealously preserved by the illustrious
astronomer's descendants:--

"LINA,--There is a great comet. I want you to assist me. Come
to dine, and spend the day here. If you can come soon after one
o'clock, we shall have time to prepare maps and telescopes. I
saw its situation last night,--it has a long tail.

"_July