1870.] Astronomy. 97 



dence, it becomes possible to estimate the rate of the star's motion. 

 Zollner believes that the probable error of a single observation will 

 correspond to a motion of less than half-a-mile per second. 



There will be an eclipse of the moon, partly visible at Green- 

 wich, on January 17th. The eclipse will begin at noon of that 

 day, and the moon will rise (at Greenwich) slightly eclipsed, and 

 obscured by the penumbra. The last contact with the penumbra will 

 take place at 5 h. 37 m. p.m. 



There will be a partial eclipse of the sun, invisible at Green- 

 wich, on January 31st. 



Jupiter will remain for some time a conspicuous object in the 

 western skies after sunset On March 18th Saturn will be in 

 quadrature preceding opposition. Venus will be at her greatest 

 brilliancy as an evening star on January 18th. 



Proceedings of the Astronomical Society. 



As usual at this season we have but one number of the Monthly 

 Notices — the supplementary number — to report on. It contains 

 but six papers, and four of these are by one author. 



Dr. 0. Pihl gives a short paper on the subject of the cluster in 

 Perseus, known as 34 Messier, which he has been studying since 

 the year 1860. He indicates certain errors in his former estimates 

 of the declinations of stars in this cluster, these errors resulting 

 from an error in one of the co- efficients employed for reducing the 

 declinations of the stars. 



Mr. Proctor supplies a calculation of the comparative clinging 

 of Venus to the solar limb during the transits of 1874 and 1882. 

 From this it appears that the interval between real and apparent 

 internal contacts will vary from 29*41 sec. to 35*11 sec. in 1874, 

 and from 20*46 sec. to 21 '39 sec. in 1882. Hence the observed 

 difference of duration, or of absolute time, in 1874 should exceed 

 the corresponding differences in 1882 in the proportion of 1*547 

 to 1, to have an equivalent value. 



He adds a note on the later transit, giving the places where 

 ingress and egress are most accelerated by parallax, as he had 

 already done for the transit of 1874. He remarks that the cor- 

 rections necessary for the transit of 1882 are much less than those 

 for the transit of 1874, not one of the places now determined 

 differing by much more than 300 miles from the place obtained 

 when phase and parallax are neglected. 



The Astronomer Koyal supplies a most valuable contribution 

 to science in the form of " A Note on Atmospheric Chromatic 

 Dispersion as affecting Telescopic Observation, and on the Mode of 

 correcting it." Every astronomical observer is familiar with the 



VOL, VII. H 



