88 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



ric observations with a Zollner's Photometer; observations of com- 

 ets, of bauds on Jupiter, of a lunar eclipse, etc., and some j)hoto- 

 hcliographic observations. 



Astrophysikalisches Institut, Potsdam. 



The buildings are well under way, and some of them are now oc- 

 cupied. Besides the 5-inch Stein heil Refractor, one by Grubb, of 

 8 inches aperture, has been in use. The principal instrument of the 

 institute, a Schroeder Refractor, of 11.7 inches aperture, is now fin- 

 ished, except the mounting. 



Dr. Spoerer observed the sun on 229 days in 1877, and on 103 

 days it was free from spots. The protuberances were also observed. 

 Dr. Vogel has investigated the spectrum of Nova Cygni, and, togeth- 

 er with Dr. Miiller, has made photometric measures in the solar spec- 

 trum. Mars and Jupiter have been studied by Dr. Lohse, who has 

 also examined the structure of solar spots. Dr. Miiller has begun a 

 series of photometric observations on the major planets. 



University Observatory, Stockholm. 



Dr. Hugo Gylden, Director. 



A 7-inch Refractor (Repsold) has been mounted, as well as a Port- 

 able Transit. The principal work of the observatory has been in 

 computation of tables (now published) for general perturbations in 

 comet orbits. 



University Observatory, Strasburg. 



Professor A. Winnecke, Director. 



The Meridian Circle is not yet mounted, and so could not be used 

 on Mars observations as was hoped. Physical observations of Mars 

 were secured on 19 days. With the small Refreictor (6-inch) on 48 

 nights 124 nebulae were observed in connection with neighboring 

 stars. 



Observations of six comets, of Nora Cygni, of double and variable 

 stars, have been made with the Equatorial. The Transit Instrument 

 has been employed by Dr. Schur, who has also observed 38 diame- 

 ters of Mars, the diameter of the moon (during the total eclipses of 

 February 27 and August 23), and a few double stars with the Jleli- 

 ometer. This instrument will next be employed in measures of the 

 solar diameters ; and this series it is intended to continue for a pe- 

 riod of eleven years. 



Dr. Hartwig has already made measures of the polar diameter on 

 G4 days, of the equatorial on 65 days, without detecting the slightest 

 difference. The diameter of Mars has been measured 30 or more 

 times, and thai of Venus on 21 days. 



