84 CONDITION OF THE SUN'S SURFACE. [MEMOIR IV. 



He will not look upon them from the present elevated 

 point of view, but regard them as results gathered with 

 much labor by a pioneer results that have had some- 

 thing to do with the development of the subject. 



The history of science shows that there have some- 

 times been occasions on which one investigator, writing 

 at an opportune moment, has carried off from his pred- 

 ecessors all the credit they were entitled to, and, per- 

 haps without any definite intention on his part, the 

 world has unjustly awarded it to him. In America, as 

 the foregoing memoirs show, some attention had been 

 paid to the use of the spectroscope long previously to 

 the time when M. Kirchoff occupied himself with the 

 subject. 



Thirteen years after the publication of the first of 

 these memoirs, M. Kirchoff (1860), in a memoir regarded 

 at that time as the origin of spectrum analysis, and en- 

 titled, " On the Relation between the Radiating and Ab- 

 sorbing Powers of Different Bodies for Light and Heat," 

 published, under the guise of mathematical deductions, 

 many of these facts as discoveries of his own. This 

 memoir appeared in German in PoggendorfFs Annalen, 

 Vol. CIX., p. 275, and was translated into English in the 

 Philosophical Magazine, July, 1860. 



Among these deductions are the following. I quote 

 M. Kirchoff's own language : 



" If a body (a platinum wire, for example) be gradu- 

 ally heated up to a certain temperature, it only emits 

 rays consisting of waves longer than those of the visible 

 rays. Beyond that point waves of the length of the ex- 

 treme red begin to appear, and as the temperature rises, 

 shorter and shorter waves are added, so that, for every 

 temperature, rays of a corresponding length of wave are 

 originated, while the intensity of the rays of greater 

 wave-length is increased. 



