VOL. XLV.] PHILOSOPHICAL TRANSACTIONS, 431 



35th Catnelopard. South of Preces- Aberra- Nutation. Mean Dist, 



Hcvelii. 38° 25' sion. tiou. South. 



1727 October 20 73"6 + 0"9 — 6"7 + 8"9 76 "7 



1728 January 12 6"0.8 1.2 + 6.1 8.8 76.9 



March 1 57.8 1.4 + 9.4 8.7 77.3 



September. . 26 75.2 2.3 — 8.8 8.1 76.8 



1729 February. . . 26 56.4 2.8 + 9-4 7.6 76.2 



1730 March 3 57-8 4.4 9.4 5.4 77.0 



1731 February. . . 5 59.1 5.6 8.5- + 3.0 76.2 

 1733 January' ... 31 64.1 8.7 8.2 — 2.9 78.1 



1738 December.. 30 6l.8 17.2 4.3 6 5 76.8 



1739 February .. . 4 06.9 17.3 8.6 6.3 76.4 



1740 January 20 56.0 18.6 7.0 —4.0 77.6 



1747 February... 27 32.3 28.5 9.4 + 8.4 78.6 



The obseiTations of the foregoing stars are the most proper, to prove the 

 change of the inclination of the earth's axis to the plane of the ecliptic; those 

 which follow will show in what manner the stars, that lie near the equinoctial 

 colure are affected, as well as others that are differently situated, with respect to 

 the cardinal points of the equator. Some of these stars are indeed more remote 

 from the zenith than I would have chosen, if there had been others, of equal 

 lustre, in more proper positions ; because experience has long since taught me, 

 that the observations of such stars as lie near the zenith, do generally agree best 

 with one another, and are therefore the fittest to prove the truth of any hypo- 

 thesis. I shall begin with those near the vernal equinox, a, Cassiopeae was com- 

 pared with the point marked 34° 55'; and at first was found to be more southerly, 

 but afterwards became more northerly than that point, as in the following table; 

 the last column of which shows its mean distance south of that point on the 

 27th of March, 1727- The observation of the 23d day of December, in the 

 year 1738, differs 3" from the mean of the others; as does also another, that 

 was taken 5 days after this; neither of which being marked as uncertain, I 

 judged it proper to insert one of them, though it gives the mean place of the 

 star near 2 seconds more northerly than any other, in a series of above lOO; 

 all of which correspond, with the mean of these here recited, within less than 

 2"; excepting two, that give the stars mean distance almost 3' more southerly; 

 but these last mentioned are marked as dubious ; and indeed they appear to have 

 been bad, by comparing them with several others that were made near the same 

 time, from which they differ almost 2". 



