THE STORY OF NINETEENTH-CENTURY SCIENCE 



so distant are they, remain mere diskless points of light 

 before the utmost powers of the modern telescope. 



All this seems wonderful enough, but even greater 

 things were in store. In 1859 the spectroscope came 

 upon the scene, perfected by Kirchhoff and Bunsen, 

 along lines pointed out by Fraunhofer almost half a 

 century before. That marvellous instrument, by reveal- 

 ing the telltale lines sprinkled across a prismatic spec- 

 trum, discloses the chemical nature and physical condi- 

 tion of any substance whose light is submitted to it, 

 telling its story equally well, provided the light be 

 strong enough, whether the luminous substance be near 

 or far in the same room or at the confines of space. 

 Clearly such an instrument must prove a veritable magic 

 wand in the hands of the astronomer. 



Yery soon eager astronomers all over the world were 

 putting the spectroscope to the test. Kirchhoff himself 

 led the way, and Donati and Father Secchi in Italy, 

 Huggins and Miller in England, and Rutherfurd in 

 America, were the chief of his immediate followers. 

 The results exceeded the dreams of the most visionary. 

 At the very outset, in 1860, it was shown that such 

 common terrestrial substances as sodium, iron, calcium, 

 magnesium, nickel, barium, copper, and zinc exist in the 

 form of glowing vapors in the sun, and very soon the 

 stars gave up a corresponding secret. Since then the 

 work of solar and sidereal analysis has gone on steadily 

 in the hands of a multitude of workers (prominent 

 among whom, in this country, are Professor Young of 

 Princeton, Professor Langley of Washington, and Pro- 

 fessor Pickering of Harvard), and more than half the 

 known terrestrial elements have been definitely located 

 in the sun, while fresh discoveries are in prospect. 



70 



