( ' 9 ° ) 
(e I had intended to infift more largely upon this 
“ Method of obtaining the Moon’s ¥ Lace, and, by 
“ Confequence, the Longitude at Sea , but that I 
“ find, that it requires a juft Treatife, too long to 
‘ e be here fubjoined : And, more efpecially, that 
“ the great Sir Ifaac Newton (to whom no Ma- 
“ thematical Difficulty is infuperable ) has been 
“ pleafed to give us a True and Thyfical Theory of 
u the Moon’s Motions, whereby the Defedts of all 
“ former Tables are fo fir amended, that it is hoped 
“ the Error may fcarce ever exceed three Minutes of 
“ Motion, or fo little in Longitude j that, perhaps, 
“ it may be thought a fufficient Exadtnefs for all the 
<c Ufes of Navigation. If therefore what is here otfer- 
“ ed find a kind Acceptance from thofe that it chiefly 
“ concerns, I fliall be encouraged to proceed on a 
“ Work I have long meditated, to improve the above- 
£ ‘ mentioned 5 Period, as to the abbreviating the Com- 
“ putation of Eclipfes , and, in general, to facilitate 
the too laborious Calculation of the Moon’s Tlace 
“ extra Syzygias. 
Not long after her late Majefty Queen Anne was 
pleafed to beftow upon the Publick, an Edition of 
the much greater, and mod valuable Part of Mr. 
Flamjleed’ s Obfervations ; by Help of which the great 
Sir Ifaac Newton had formed his curious Theory 
of the Moon, a firft Sketch of which was inferted 
by Dr. David Gregory in his AJironomia Thy fie te 
& Geometric a Element a, pubiiffied at Oxford , 
1701 j and again, in the fecond Edition of Sir Ifaac s 
Trincipia , which came out in 1713, we have the 
fame 
