( «pt ) 
fame revifed and amended by himfelf, to that De* 
gree of Exadnefs, that the Faults of the Computus 
formed therefrom rarely exceed a quarter Part of 
what is found in the belt Lunar Tables before that 
Time extant. 
Being thus provided with proper Materials, viz. 
a large Set of Obfervations, and a Theory of the 
Motions fo very near the Truth, I refumed my for- 
mer Defign of filling up my Abacus or Synopjis of 
the Defeds of this Lunar Theory, and made fables 
to expedite the Calculus according thereto, and com- 
pared the Numbers thereof with many of the moft 
certain of Mr. Flamjieed'i Places obferved. By this 
it was evident that Sir 1/aac had fpared no Part of 
that Sagacitv and Induftry fo peculiar to himfelf, in 
fettling the Epoches , and other Elements of the Lu- 
nar AJlronomy , the Refult many times, for whole 
Months together, rarely differing two Minutes of Mo- 
tion from the Obfervations themfelves ; nor is it un- 
likely but good Part of that Difference may have 
been the Fault of the Obferver. And where the Er- 
rors were found greater, it was in thofe Parts of the 
Lunar Orb where Mr. Flamjleed had very rarefy 
given himfelf the Trouble of obferving ; viz. in the 
third and fourth Quarter of the Moon' s Age, where 
fometimes thefe Differences would amount to at lead 
five Minutes. 
Mr. Flamjleed was long enough pofieffed of the 
Royal Obfervatory to have had a continued Series of 
Obfervations for more than two Feriods of eighteen 
Years j by which he had it in his Power to have 
done all that could be expeded from Gbfervation, 
towards 
