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LI II. The Refolution of a General Propcftion 
jor Determining the horary Alteration of 
the P oft ion of the Ter refl rial Equator , from 
the Attraction of the Sun and Moon : With 
fc7?te Remarks on the Solutions given by 
other Authors to that difficult and impor- 
tant Problem . By Mr . Tho. Simpfon, 
F. R. S. 
Read Dec. 32, ^INCE the time, that that excellent 
^ Aftronomer, my much honoured 
friend Dr. Bradley, publifhed his obfervations and 
difcoveries concerning the inequalities of the preceffion 
of the equinox, and of the obliquity of the ecliptic, 
depending on the pofition of the lunar nodes, ma- 
thematicians, in different parts of Europe, have fet 
themfelves diligently to compute, from phyfical prin- 
ciples, the effects produced by the fun and moon, in 
the pofition of the terreftrial equator; and to examine 
whether thefe effedts do really correfpond with the 
obfervations 
Two papers on this fubjedt have already appeared 
in the Philofophical Tranfadtions ; in which the au- 
thors have fliewn evident marks of fkill and penetra- 
tion. There is, neverthelefs, one part of the fubjedt, 
that feems to have been paffed over without a due de- 
gree of attention, as well by both thofe gentlemen, 
as by Sir Ifaac Newton himlelf. 
This part, which, upon account of phyfical diffi- 
culties, is indeed fomewhat flippery and perplexing, 
I fhali make the principal fubjedt of this effay. 
Gene- 
