( 1 86 ) 
“ and Laft Quarters of the Moot, h ^4ge, when her 
“ weaker Light does not fo much efface that of the 
“ Stars. Whereas the Eclipfes of the Satellites of 
“ Jupiter , how proper foever for Geographical 
“ Purpofes, were abfolutely unfit at Sea, as requi- 
“ ring Telefcopes of a greater Length than can well 
be direfted in the rolling Motion of a Ship in 
« the Ocean. 
« Now the Motion of the Moon being fo fwift, 
** as to afford us fcarce ever lefs than two Minutes for 
“ each Degree of Longitude, and fom'etimes two 
“ and a half ; it is evident, that were we able per- 
“ feftly to predift the true Time of the Appulfe or 
“ Occultation of a Fix’d Star, in any known Meridi- 
* c an, we might, by comparing therewith the Time ob- 
“ ferved on Board a Ship at Sea, conclude fafely how 
« much the Ship is to the Eaftward or Weft ward of the 
“ Meridian of our Calculus. 
** But after much Examination, and carefully col* 
“ lating the Caroline Tables of Mr. T. Street (though 
“ generally better than thofe that went before him) 
“ as likewife thofe of Tycho , Kepler , BuTHaldus, and 
“ our Horrox , with many accurate Obfervations of 
“ the Moon* carefully made on Land j it does not ap- 
‘‘ pear that any of thefe Tables do reprefent the Moti- 
“ ons with the Certainty required j and though many 
*« times the Agreement feems furprizing, when the 
“ Errors of the feveral Equations compenfate one ano- 
« ther ; yet in thofe Parts of the Drb where they 
“ all fall the fame Way, the Fault is intolerable, and 
“ the Refult many times not to be depended on, to 
“ more than one hundred Leagues \ that is to fay, it is 
“ wholly infufficient. 
“ Yet 
