EXPLORING THE GLORIES OF THE FIRMAMENT 



155 



Photograph from Yerkes Observatory 



THE MOON AT EIGHTEEN DAYS OLD 



By measuring the length of their shadows, astronomers have been able to determine the 

 height of the mountains of the moon. Mount Newton is 24,000 feet high, and there are 

 twenty-eight that are more than three miles high. There are volcanoes on the moon with 

 diameters of 125 miles. 



way, though he made no charges that 

 such was the case. 



"More than a century later another 

 astronomer came along — Bessel was his 

 name — and he undertook to interpret my 

 behavior. Although I was forty-seven 

 trillion miles away from him, he and 

 his pupil, Peters, pronounced me a 'gay 

 dog,' with an affinity they could not see, 

 though only because they lacked tele- 

 scopes powerful enough. They said my 

 affinity and I were coming in the sun's 

 direction, overtaking that luminary at 

 the rate of nearly six miles a second, 

 and that we traveled around a common 



center of gravity once every 48.8 years. 

 "Another half century passed, and 

 meanwhile telescopes were undergoing 

 improvement. The circumstantial evi- 

 dence against me was mighty strong, but 

 still no one had yet seen my affinity, and 

 I felt pretty safe. Then came along that 

 gifted optician, Alvan G. Clark. He was 

 adjusting what is now the Dearborn Ob- 

 servatory telescope. When he trained 

 that instrument on me. I saw that the jig 

 was up with my secret. My affinity her- 

 self was seen, and I have to admit that 

 Bessel and Peters knew what they were 

 talking about." 



