The Romance of the Heavens 47 



future. But we have seen enough to convince us that, whatever 

 advances the future holds in store, the science of the heavens 

 constitutes one of the most important stones in the wonderful 

 fabric of human knowledge. 



ASTRONOMICAL INSTRUMENTS 



1 



The Telescope 



The instruments used in modern astronomy are amongst 

 the finest triumphs of mechanical skill in the wtorld. In a great 

 modern observatory the different instruments are to be counted 

 by the score, but there are two which stand out pre-eminent as 

 the fundamental instruments of modern astronomy. These in- 

 struments are the telescope and the spectroscope, and without 

 them astronomy, as we know it, could not exist. 



There is still some dispute as to where and when the first 

 telescope was constructed; as an astronomical instrument, how- 

 ever, it dates from the time of the great Italian scientist Galileo, 

 who, with a very small and imperfect telescope of his own inven- 

 tion, first observed the spots on the sun, the mountains of the 

 moon, and the chief four satellites of Jupiter. A good pair of 

 modern binoculars is superior to this early instrument of Gali- 

 leo's, and the history of telescope construction, from that primi- 

 tive instrument to the modern giant recently erected on Mount 

 Wilson, California, is an exciting chapter in human progress. 

 But the early instruments have only an historic interest: the era of 

 modern telescopes begins in the nineteenth century. 



During the last century telescope construction underwent 

 an unprecedented development. An immense amount of inter- 

 est was taken in the construction of large telescopes, and the 

 different countries of the world entered on an exciting race to 

 produce the most powerful possible instruments. Besides this 



