of the New Berlin Astronomical Ephemer is. 251 



indebted to the persevering industry of Messrs. Herter, Wok 

 fers, and Deinhardt, who have divided between them the cal- 

 culation of all the longitudes and latitudes, as well as right 

 ascensions and declinations, immediately from the tables. This 

 being the first considerable astronomical calculation executed 

 by any of these gentlemen, no pains have been spared to dis- 

 cover and to correct all errors by taking the first four differ- 

 ences. Wherever a correction of 0"\5 would bring out more 

 regular differences, the whole calculation has been revised. In 

 a few such cases it was necessary to retain the calculated num- 

 bers unchanged ; and this quantity may therefore be consi- 

 dered as the maximum of error. Errors of 0"'3, and less, could 

 not be avoided, on account of the great number of equations. 

 The parallax and semidiameter have been put to the same 

 test. The manner of calculating the other columns will be 

 given in another place. This section is concluded by a table 

 in which the apparent obliquity of the ecliptic, the true paral- 

 lax of the sun, the aberration of the sun's longitude, the equa- 

 tion of the equinoctial points, and the longitude of the moon's 

 node, have been placed together for every tenth day. The 

 aberration is to be added algebraically with the sign given to 

 it to the values contained on page II., in order to obtain the 

 real longitude of the sun, as it will be observed. The sign of 

 the equation of the equinoctial points denotes that the mean 

 equinox is in this year behind the true equinox, or that all 

 mean longitudes are greater than the true ones. The moon's 

 node is given according to Burckhardt. 



Next follow the ephemerides of the planets and satellites. 

 For the older planets the page on the left contains the helio- 

 centric places, together with the columns of rising and set- 

 ting ; while that on the right contains the geocentric places, 

 with the passages over the meridian in mean time, the former 

 referred to the ecliptic, the latter to the equator, the right as- 

 cension being given in time. For Mercury and Venus the 

 places have been calculated for every other day, and the mean 

 noon at Berlin ; for the others they are calculated for every 

 fourth day, and the mean midnight at Berlin. 



The calculations for Mercury have been undertaken by 

 Mr. Herter. One of the corrections of the tables of M. Lin- 

 denau, first noticed by Professor Schumacher, which refers to 

 the radius vector, has been inadvertently omitted. This trifling 

 neglect affects, however, the last figures only of the radius 

 vector, and seems to lie within the limits of uncertainty of even 

 Lindenau's tables. The fourth differences have likewise been 

 taken in this case, but their magnitudes were in some parts 

 such as to afford no certain criterion of the absolute correct- 



2 K 2 ness 



