Berlin Astronomical Ephemerisfor 1832. 83 



and Venus, and M. von Heiligenstein has kindly calculated the 

 positions of Ceres by his own elements, and those of Uranus; 

 the latter calculations perfectly agree with those of M. Wolfers. 

 The places of the stars have been taken from those tables by 

 which Bessel has again afforded one of the most important 

 auxiliaries, for the accurate ascertainment of all the principal 

 elements of astronomy, whose determination was before al- 

 ready, for by far the greatest part, his own work. He has had 

 the kindness to communicate to me those tables in manu- 

 script. 



The somewhat smaller number of occultations of stars in 

 this year does not arise from a less careful research, but is 

 principally owing to the circumstance that the moon no more 

 passes through the Hyades. This year is however by no means 

 destitute of important occultations, especially in the case of 

 planets, among which there is a visible occultation of Mercury, 

 which is rather a rare phenomenon. It is likewise distin- 

 guished by a transit of Mercury, visible in all Europe, and 

 the transition of the plane of the ring of Saturn through the 

 earth and the sun. It would appear that the latter may be 

 well observed in the morning hours of December, and these 

 observations will perhaps assist in deciding the famous ques- 

 tion regarding the period of the rotation of the ring. 



In selecting the stars on the parallel of the moon for this 

 year's Ephemeris, a somewhat different principle has been 

 adopted. Mr. Baily has had the kindness to furnish me with 

 a copy of his catalogue of zodiacal stars, from which all those 

 stars have been expunged, which, on account of their inferior 

 light or their vicinity to bright stars, or the possibility of mis- 

 taking them for others, appeared less adapted to serve as 

 points of comparison. He expressed, at the same time, the 

 wish that certain stars which he pointed out as convenient, 

 on account of their declinations, for corresponding altitudes, 

 especially in the Observatories of the southern hemisphere, 

 should have a mark of distinction added to them. The stars 

 thus referred to are marked with an asterisk in this year's ca- 

 talogue. 



Mr. Baily however principally wished, and Prof. Struve 

 agrees with him on this point, that in future always one star 

 at least should be common to the successive evenings, in order 

 to afford to travellers in distant regions a means of accurately 

 determining the rate of their time-pieces, as also that, like- 

 wise for the advantage of such travellers, the selection of the 

 stars should be made according to the true declination of 

 the moon. Now although this principle of selection has for 

 European Observatories the disadvantage, that astronomers 



M 2 must 



