468 AstronuDiy. 



them appear more early in the j'ear. There is no man, to 

 Avhom the world is more indebted for astronomical informa- 

 tion, than to ]\I. Schumacher : and we are persuaded that 

 from his known liberality of sentiment, he will excuse these 

 remarks. — The work in question contains the apparent places 

 (both in right ascension and declination) of the 36 principal 

 stars, for every 10th day in the year; together with the ap- 

 parent place of the pole-slar and of 8 Ursce Minoris, for every 

 day in the year, at the time of their upper and lower culmina- 

 tions. Likewise the geocentric position of Mercuiy, Jupiter, 

 Saturn and Uranus for every day in the year : and their pa- 

 rallax and semidiameter at given portions of the year. There 

 is also given for every day in the year, not only the sidereal 

 time at apparent noon, but likewise the sidereal time at mean 

 noon ; and a logarithmic number (denoted by ju.) which is very 

 useful in computing the time by equal altitudes, from a for- 

 mula given originally by Gauss, and from which some very 

 useful tables have been computed by M. Gerling. The longi- 

 tude of the sun, for every day in the year, and the logarithm 

 of its distance (to seven places of figures) are also subjoined : 

 and the work closes with a small table of the logarithms of 

 A and B for every 10th day in the year, for computing the 

 precession, aberration and nutation, agreeably to the method 

 alluded to by Mr. Baily in our Number for March last. 



]M. Schumacher is also publishing another work, entitled 

 Astro7iomische Ahhandlungen, the first part of which contains 

 a list of all the comets that have been recorded ; with the com- 

 putations of their elements, by Dr. Olbers. In this list we 

 notice the periodic comet observed last year by Mr. Rumker 

 at New South Wales. Its first recorded appearance was in 

 1786, afterwards in 1795, 1805, 1819, and lastly in 1822: its 

 revolution is performed in about 1205 days. The re-discovery 

 of it, last year, by Mr. Rumker, has confirmed the fact of its 

 revolution; and the result is certainly one of the proudest 

 triumphs of modern science. 



In the Milan ephemeris for ] 823, which has also just reached 

 this country, the editors have studied the convenience of those 

 practical astronomers who observe the moon, by giving her 

 right ascension and declination, at the time of her passing the 

 meridian. 



In M. Schumacher's Astronomische Nachrichten, No. 29, are 

 inserted upwai'ds of 300 observations of the moon and certain 

 stars isoithin a short distance of her, when on the meridian, by 

 M. Bouvard of the Royal Observatory at Paris ; for the pur- 

 pose of determining the difference of longitude fi-om other ob- 

 servatories, where similar observations have been made. This 



neiB 



