Mathematical tracts on the lunar and planetary theories, the figure of the earth, precession and nutation, the calculus of variations, and the undulatory theory of optics.

216 PRECESSION AND NUTATION.
51. The values of a and b, according to the observations of most astronomers, are 50",1 and 9",6. Substituting
these in the formulae above, n = 68,9, and B =,0029225.
Assuming the law of density mentioned above, qc = 160~. 53',
and
e =,0030812 = —
324,5
52. Dr Brinkley, in the Philosophical Transactions
for 1821, has reduced the value of b to 9",25. This gives
~n = 78,2 and B =,0031911; thence qc = 149.10', and
1
e =,0032973 ---
303,3