Davis’s Report on the Nautical Almanac. 325 
anew according to the method of least squares, and the work is 
left in such a form that the observations of all observatories, par- 
ticularly those of Washington and Greenwich, on account of the 
complete form in which they are given to the world, can be used 
from year to year for the continued improvement of the elements 
of the planets. ‘The perfection of the places of these planets is 
the more important and valuable that they are used very con- 
stantly in lunar distances by the navigator, aud their errors are 
highly magnified at the time they are best seen and most useful, 
by the greater relative change in their distances from the earth 
than in those of the other planets employed in this way. 
{n preparing the ephemeris of Jupiter and that of Saturn, as 
well as in those of the preceding planets, all the errors and alter- 
ations pointed out by Professor Airy in the introduction to the 
Greenwich Planetary Reductions, have been corrected and adopted, 
and the tables of Bouvard and Lindenau have been entirely re- 
modelled and reconstructed for the convenience of computation. 
Bat it is well known to astronomers, that the theory of Jupiter 
and Saturn demands a thorough revision, and their combination 
presents a case of peculiar difficulty which has been ably treated 
by Professor Hansen. To prepare Hansen’s theory for use in 
practical computation, is a work of time. It will be entered 
upon immediately, and will probably by completed in the course 
of two years. . 
‘With regard to the new planet Neptune, the world has already 
accepted with grateful acknowledgments the labors which Ameri- 
can astronomers have bestowed upon it with illustrions success. 
‘he computation of the tables of the perturbations of Neptune 
Vv Prof, Peirce, and the computation of the elliptic elements of 
Neptune by Mr. Sears C. Walker, have resulted in the prepara- 
tion of an ephemeris by the last named gentleman, which admits 
of no sensible correction. Observation has proved, up to this 
cision, ‘Dutation, and aberration. In this improvement, it is just 
Stoonp Sentes, Vol. XIV, No. 42.—Nov., 1852. 42 
