150 
SECOND REPORT - 1832 . 
that the mass ought to be increased. But as no other errors 
were taken into account, no great value can be attributed to 
this result. 
In 1804, Zach published complete Tables of the Sun, founded 
on the observations made at Gotha. In 1806, the French Board 
of Longitude published Delambre’s Solar Tables, which (till 
within a short time,) have been generally adopted. They were 
founded on observations by Bradley, Maskelyne, and Delambre, 
and on Laplace’s theory; the masses of Venus and Mars, as 
well as the other elements, being determined by the discussion 
of the observations. In 1809, Zach published his Tables 
abregees et portative s> differing little from the larger Tables 
except in the arrangement, which, giving more trouble to the 
computer, required less space. In the Milan Ephemeris 1810 
and 1811, Carlini published his Solar Tables. By a new arrange- 
ment (making the difference of successive values of the argu¬ 
ments the same as the alteration due to one day), he has di¬ 
minished very much the labour of calculating a solar ephemeris; 
though for the calculation of an independent place, his system 
gives no particular facilities. The elements of these Tables are 
the same as those of Delambre’s. In the Conn . des Temvs for 
-L 
1816, Burckhardt gave the results of a comparison of Delam¬ 
bre’s Tables with a great number of Maskelyne’s observations 
(far greater than the number on which they were founded). It 
appeared that the epoch, the perigee, and the eccentricity, re¬ 
quired sensible alterations, and that the mass of Venus ought 
to be reduced about *th, and that of the Moon to be sensibly 
diminished. In Lindenau’s Zeitschrift for 1817, Littrow arrived 
at nearly the same results, except that he diminished Mars 
considerably. In the Phil. Trans. 1826, Sir James South gave 
86 observations of the Sun, compared with the Tables ; which I 
discussed in the Phil. Trans. 1827. In 1827 the writer of this 
paper compared Delambre’s Tables with 1200 Greenwich obser¬ 
vations made with the new transit, and deduced from them the 
corrections in the elements. These agreed closely, in general, 
with Burckhardt’s, excepting that a diminution of Mars appear¬ 
ed necessary. Some discordancies however led him to suspect 
the existence of an inequality that had escaped the sagacity of 
Laplace and Burckhardt, and a new term was at length found 
and calculated. This was announced in the Phil. Trans. 1828. 
Corrections founded on these alterations of the elements have 
for some years been published in the Nautical Almanac. In 
the AstronomischeNachrichten^os. loo and 134,(March 1828,) 
Bessel gave the result of a discussion of Bradley’s and his own 
observations. Adopting Burckhardt’s masses of Venus and 
Mars, and a mass of the moon nearly corresponding to Lin- 
