REPORT OF COMMITTEE ON OBSERVATORIES 1 57 



scarcely be found, but in place of that I think that the location of 

 the Flagstaff observatory would be an admirable substitute. Among 

 the solar investigations, I hope an effort will be made to get at the 

 differences in radiation from different spots on the sun's surface in 

 their successive rotations, so as to get the chronological variations 

 in temperature, as well as the geographical differences. The com- 

 plete course of work that you have sketched out covers all the prob- 

 lems that have thus far been found worthy of study, and, of course, 

 the observatory will take up new ones as fast as they develop. 



I should not encourage duplicating in the southern hemisphere all 

 the investigations that are to be conducted in the northern, but there 

 are some problems that could advantageously be studied at both 

 observatories. On account of our knowledge of atmospheric con- 

 ditions at the stations Charcani and El Misti, that location has some 

 advantages, but there is still hope of finding an equally advantage- 

 ous location on the mountains of Ecuador or southern Colombia. 

 When such a station is found, it should be devoted especially to 

 studies on nebulae and stars, such as are described in your article 3, 

 and perhaps also to less extensive studies on the determination of 

 the solar radiation constant. 



From a meteorological point of view, observations on these northern 

 and southern mountain stations are extremely desirable, and espe- 

 cially if observers at the upper and lower stations can make absolute 

 determinations of the altitudes and motions of the clouds or tempera- 

 tures of the upper air by means of kite and balloon ascensions. 

 Many other studies into the physics of the atmosphere, such as its 

 gaseous constituents, its dust, and its motions, would constitute 

 valuable additions to our meteorological knowledge. The special 

 field to be occupied by such an observatory relates to the highest 

 attainable atmospheric strata. 



If there is any specific matter on which I can be of use to your 

 Committee, I shall always be happy to respond. 



[From Professor G. Midler, Royal Astrophysical Observatory , Potsdam, 



Germany. ~\ 



[Translation.] 



April 4, 1903. 

 The plan to establish a great astrophysical observatory at a par- 

 ticularly favorable site, and to provide it with the best instrumental 

 equipment, will be greeted everywhere with lively interest. For 



