Page:Sir William Herschel, his life and works (1881).djvu/66

44 "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."

While was measuring these lunar mountains, in December, 1779, he made by chance an acquaintance of much value to him. Dr., 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 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