ut this time another change was made to the house 19 New King Street,
which was the last move in Bath. It was here that the _Georgium Sidus_
was discovered.

The music still went on. The oratorios of the _Messiah_, _Judas
Maccabeus_, and _Samson_ were to be performed under HERSCHEL'S
direction, with an orchestra of nearly one hundred pieces. The scores
and vocal parts of these CAROLINA copied with her own hands, and the
_soprani_ were instructed by her, she being the leading soloist. Along
with the music went the astronomy. Not only were new telescopes made,
but they were made for immediate use.

The variable star _Mira Ceti_ was observed, and a long series of lunar
observations begun.

"In 1779, 1780, and 1781 I measured the heights of about one hundred
mountains of the moon, by three different methods.

"Some of these observations are given in _Philosophical
Transactions_, vol. LXX., but most remain uncalculated in my journal
_till some proper opportunity."[12]_

While HERSCHEL was measuring these lunar mountains, in December, 1779,
he made by chance an acquaintance of much value to him. Dr. WILLIAM
WATSON, a Fellow of the Royal Society, distinguished for his researches
in electricity, happened to see him at his telescope, and this led to a
visit and an invitation to HERSCHEL to join the Philosophical Society of
Bath, then forming. This he gladly did, and it was of use to him in many
ways.

He there formed acquaintance with men of his own way of thinking, and he
himself became known. Better than all, he learned to measure himself
with other men, and by his early papers read to the Society, he gained
skill in putting his thoughts before his hearers. This skill he never
lost, and the merely literary art of his memoirs would make his papers
remarkable without their other merits. He is always clear, and in his
early papers especially, he appeals to his particular audience--the
Royal Society--in a way which shows that he is conscious of all its
weaknesses as well as of its dignity. Later, his tone slightly changed.
He became less anxious to win his audience, for he had become an
authority. This knowledge lent a quiet strength to his style, but never
induced the slightest arrogance of spirit or manner.

The Bath Philosophical Society has left no printed proceedings. HERSCHEL
was one of its earliest members, and many papers were communicated to it
by his hand. These appear to have been of a very m