William Watson, Jr., and was read May 11, 1780, at the same time as the other paper on the mountains of the moon. It is to be noted that Herschel was at this time plain "Mr. William Herschel, of Bath." It was only in 1786 that he became "Dr. Herschel," through the Oxford degree of LL.D.
Neither of these two papers is specially remarkable on its purely astronomical side. The problems examined were such as lay open before all, and the treatment of them was such as would naturally be suggested.
The second of these two contained, however, a short description of his Newtonian telescope, and he speaks of it with a just pride: "I believe that for distinctness of vision this instrument is perhaps equal to any that was ever made." He was, at least, certain of having obtained excellence in the making of his instruments.
In his next paper, however, read January 11, 1781, a subject is approached which shows a different kind of thought. It is the first obvious proof of the truth of the statement which he made long afterwards (1811),
