54 HERSCHEL AND HIS WORK 



observe and measure as well. He was one of a race of 

 working astronomers of whom England had cause to 

 be proud. They might be called, but they were not 

 amateurs. 



The second paper, read the same day, and headed 

 " Astronomical Observations relating to the Mountains 

 of the Moon," was more ambitious, and formed a better 

 prelude to the path of discovery, on which Herschel 

 would soon enter. He begins with an apology for 

 attempting to ascertain the height of the lunar moun- 

 tains, but a "knowledge of the construction of the 

 moon leads us insensibly to several consequences, 

 which might not appear at first ; such as the great 

 probability, not to say almost absolute certainty, of 

 her being inhabited." He is equally certain that 

 the moon rejoices in an atmosphere like the earth's. 1 

 Passing over this scientific faith, in the meantime, 

 as a heritage he received from the past but had not 

 examined, we find him boldly venturing to dispute 

 the conclusions arrived at by Galileo, Hevelius, and 

 others of great name. Galileo had made the lunar 

 mountains higher than any then known on the earth, 

 five and a half miles; but Hevelius reduced this 



1 In 1762, Samuel Dunn, from "a nice examination of the two ends 

 of Saturn's ring, at sucli time when the planet is on the dark edge 

 of the moon," came to the conclusion "that this diversity of appear- 

 ance must have arisen from the effects of an atmosphere of the moon." 

 Previously, he states, the existence of an atmosphere was much de- 

 bated, and is "still undecided" (Phil. Trans, for 1761-2, vol. lii. p. 580). 



In a paper read before the Royal Society on November 27, 1766, 

 the Prince de Croy expresses doubts about the existence of a lunar 

 atmosphere, but "I am inclined to believe," he says, "there is no 

 water in the moon." He also states that the hollows between the 

 mountains marked on his diagram are surprising on account of their 

 depth. 



