This incident took place in the winter of 1775, at a house situated
near Walcot turnpike, to which Herschel had removed in the summer of the
previous year. Here, on a grass plot behind the house, he made active
preparations for the erection of a twenty-foot telescope. So assiduous
was his devotion to this work, that while he was engaged in polishing
the mirror, his sister was constantly obliged to feed him by putting his
victuals into his mouth. Otherwise he would have reduced himself to a
condition of positive emaciation! Once, when finishing a seven-foot
mirror, he did not take his hands from it for sixteen consecutive hours;
for in these days machinery had not been devised as a substitute for
manual toil. He was seldom unemployed at meals; but at such times
employed himself in contriving or making drawings of whatever occurred
to his fertile fancy. Usually his sister Caroline read to him while he
was engaged at the turning-lathe, or polishing mirrors; choosing such
books as "Don Quixote," the "Arabian Nights," the novels of Sterne and
Fielding; and tea and supper were served without any interruption to the
task in which Herschel was absorbed.

In Miss Herschel's charming letters we find a vivid sketch of the
family avocations at this period:---


"My brother applied himself to perfect his mirrors, erecting in
his garden a stand for his twenty-foot telescope: many trials
were necessary before the required motions for such an unwieldy
machine could be contrived. Many attempts were made by way of
experiment against a mirror before an intended thirty-foot
telescope could be completed, for which, between whiles (not
interrupting the observations with seven, ten, and twenty-foot,
and writing papers for both the Royal and Bath Philosophical