1 
( ‘48 ) 
the contrary .Way ; and that it will be found at laid, 
“ that the Fluent of any rational Fluxion whatever, 
does depend upon the Meafiires of Ratio’s and 
“ Angles, excepting thole which may be had in finite 
“ Terms even without introducing Meafures. 
Dr. Tailor knowing by this Letter what the Au- 
,thor had done, was pleafed to propofe the Invention 
of the Fluents of the two lall Fluxions as a Problem 
to the Mathematicians in foreign Parts. Mr. Ber- 
mullt in the Le'tffic A 6 is of 17x9.^. X56, did lliew 
accordingly how they are reducible to Conic 
JVrea’s. The Editor has publillied the Author’s own 
Solution by Meafures of Ratio’s and Angles ; and upon 
this Foundation has condriKded new Tables of Logo- 
metrical and Trigonometrical Theorems, for the F luents 
of Fluxions reduced to 94 Forms, part rational and part 
irrational. . He has likewife added general Notes upon 
the chief Difficulties in the Book, together with a Me- 
thod of compofing Synthetical Demonllrations of Lo- 
gometrical and Trigonometrical Conltrucifions, illu- 
Rrated by various Examples. 
The firfi; Treatife in the Mifcellaneous Works is 
concerning x}a^Eflimatton of Errors in Mixt Mathe- 
matic ks. It confifhs of 2 8 Theorems, to determine the 
Proportions among the leall contemporary Variations 
of the Sides and Angles of Plane and Sphserical Tri- 
angles, while any two of them remain invariable. An 
Example will fliew their great Ufe in Altronomy. The 
Time of the Day or Night is frequently to be deter- 
mined by the Altitude of fome Star. Let it then be 
propofed to find the Error, that may arife in the Time, 
•from any given Error in taking the Altitude. By ap- 
plying the 2id Theorem to the Triangle form’d by the 
Complements of the Star’s Altitude and Decimation 
and 
