54 HERSCHEL AND HIS WORK 



observe and measure as w< 11. II. was one of a race of 

 working astronomers of \vlni Ku-laiKl ha. 1 cause to 

 be proud. Tlu-y mi-jlit !> called, hut th y w -iv imt 

 amateurs. 



Tin- sinui'l piper, read the same day, anl headed 

 "Astronomical Observations relating to tin- Mountains 

 of the Moon," was more ambitious, a D<] form* 

 prelude to the path of discovery, on which II. 

 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 meant inn-. 

 as a heritage he received from the past but hal not 

 examined, we find him boldly venturing to dispute 

 the conclusions arrived at by Galileo, Hevelius, and 

 others of great name. Galileo had made tin- 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 such 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. Hi. 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. 



