ASTRONOMY. 163 



Bonn : Zone 50°-40o. The obseiAatious are not yet finished, although 

 near to completion. The mean dillereuce of K. A. of a star from two 

 observations is about 0^.08 and I'M. Investigations of the efiect of the 

 magnitude of a star on its deducetl R. A. show a difference (faint minvs 

 bright) less than + 0.^008 in the mean. 



Lund : Zone 40O-35o. The work is nearly completed. 



Leyden : Zone 350-30°. The observations are finished. 



Camhridge (England): Zone 30O-li5o. Thirty-eight thousand five hun- 

 dred and fifty- nine observations have been made from 1872 to 1883. 

 Three hundred and eighty-four stars have not yet been observed once; 

 614 have been observed only once; the rest of the total number, 10,G91, 

 twice or often er. 



Berlin : Zone 2oO-20o. Dr. Becker's observations are completed. 

 Observations on 13 nights of 247 stars show that fainter stars are ob- 

 served later by 0^.007 for each magnitude. 



Berlin : Zone 20°-15°. Dr. Auwers has long since comi)leted the 

 observations. The reductions are not completed. 



Leipsic : Zone 15°-5°. The observations are nearly completed for 

 the zone 150-10°, and those for 10^-50 are in progress. 



Albany : Zone 5°-lo. The observations are completed, and the re- 

 ductions very far advanced. 



Nikolaieff : Zone -|-lo-2°. The observations are still in progress. 



Determining stars for the southern zones of the Astronomische Gesel- 

 schaft. — These 303 stars are being observed at various observatories, 

 as follows : 



Gape of Good Hope. — The observations are finished and each star has 

 been observed at least twelve times. The results of observation are all 

 reduced, and for the final publication there are needed investigations 

 of the flexui-e, the latitude, the refraction, the personal equations of 

 the observers depending («) on the star's magnitude, (b) on its declina- 

 tion. The division errors for each 1° have been investigated. The cir- 

 cle is not reversible. The tiexure is to be investigated by means of col- 

 limators made specially for the purpose byTroughton & Simms. Each 

 collimator is furnished with a reversing apparatus and a level, and the 

 horizontal point can thus be determined, either north and south. Com- 

 bining these horizontal points with nadir-points will determine whether 

 the flexure is the same looking north and south. The latitude is to be 

 determined from observations of circumpolar stars, at both culminations 

 (already observed in 1S80 '81 '82 '83). The declinations of these stars 

 are to be determined by observing their azimuths at greatest elonga- 

 tions E. and W., with the 3-foot theodolite of the India survey. South 

 stars culminating at zenith-distances, equal to those of the circumpolar 

 stars, are to be observed by Talcott's method. These observations are 

 to be combined by Kapteyn's method. 



For the refraction, the Cape has observed a number of north stars 

 (near the zenith of Leyden) and zenith stars (near the horizon of Ley. 



