134 THE NATIONAL SCIENTIFIC INSTITUTIONS AT BERLIN. 



of mechanics of the heaveus ; and tlie physical conditions of the stars 

 received but occasional, and more accidental than systematic, attention 

 from a few astronomers. Astro-physics had not fully developed itself as 

 a branch of astronomy. When, then, later, more attention was given to 

 certain changes on the surface of the sun and to other phenomena, the 

 observations were restricted to the use of such apparatus as was then 

 found in a well-equipped observatory, and not much difficulty was expe- 

 rienced in combining new requirements with the existing apparatus. It 

 was not until the more extending field of study brought physical and 

 chemical examinations in contact with the astronomical, and more es- 

 pecially since theapplication ot]the spectral analysis upon the astro-phys- 

 ical investigations proved the most powerful means for the discovery of 

 the substances of which the heavenly bodies are composed, and since 

 photograph}^ had begun to be employed in fixing certain events observed 

 in the skies, it was not until then that the needs of separate establish- 

 ments was fully recognized, equipped with suitable instruments not re- 

 quired by observatories of the older kind. Such an establishment is 

 now found in the Astro-physical Observatory at Potsdam. 



As early as 1860 it was suggested to establish, in the vicinity of Berlin, 

 an Observatory for the physical examination of the sun. The conditions 

 however were then not favorable, and it was not until 1871 that the 

 first steps were taken towards the realization of the project. The Crown 

 Prince, whose attention had been called to the effort by Prof. D. Schell- 

 bach, managed to have propositions invited with regard to the subject 

 from the director of the Berlin Observatory to which it was planned to 

 connect the proposed solar observatory. To this the director responded 

 on September 30, 1871, by submitting a memorial. It was proposed to 

 establish an observatory in the vicinity of Berlin well-equipped for the 

 direct, spectroscopic, and photographic investigation of the surface of 

 the sun, this observatory at the same time to be the central station for 

 magnetic and meteorological observations. 



The Academy of Sciences, at the request of the Government, on April 

 29, 1872, while recognizing the interest of the subject, objected to the 

 execution of the proposition from the standpoint that the scientific re- 

 quirements would demand the establishment of two institutes, of which 

 one should be devoted to astro-i)hysics and the other to tellurian phys- 

 ics ; it opposed an organic combination of the two on the ground that 

 its scope would be too large for a successful administration. In this 

 case however the observations of the sun would have to form but a 

 part of the labors of the astro-physical institute. 



The Minister of Education then called together a special commission 

 under the presidency of Privy Counsellor E. du Bois-Reymond, which, 

 in accordance with the academic consideration, recommended at first 

 the establishment of an astrophysical observatory, with the proviso, 

 however, that, in the case of uncertainty of the early erection of a tel- 

 lurian observatory, such magnetic observations should be provided for 



