Life of John Bevis, M.D.F.Ii.S. &'c. iMT 



•from m to a, as the foregoing calculations ha\'« supposed ; 

 but will be from p to a. "it is, however, very evident, that 

 if ma be a minimum, the linepw, when sp is given, will 

 slso be a minimum , and if all the ma's in fig. 4. are mi- 

 nima, it follows also that all the .vp's, whatever they may 

 be, will give the pa's as small as possib'le : and this is the 

 point that was to be established. 



Whatever, therefore, mny be the sura of real motions re- 

 quired to account for the phrenomcna of proper motions, 

 ■our foregoing argument? cannot be afiected by the result; 

 for, as by observation it is known that pro[)ei' moticmd do 

 exist, and since «o solar motion can resolve them entirely 

 into parallactic ones, we ought to give the prel'ercnce to 

 that direction of the motion of the sun which wi^l take away 

 more real motion than any other, and this, as we have 

 shown, will be done when ihe right ascension of the apex 

 is 243° 5\i' 30", and its north polar distance -iO" 22'. 



XLVr. Life o/ John Bevis, M. D. F. R. S. &r'. fow- 

 vuitiicaitd by Mr. T. S. Evans, of the Royal Military 

 Academy y JVoolwich. 



John Bevis, M.D., feHow of, the Royal Society of Lon- 

 don, and corresponding member of lire Academy of Sciences 

 of Paris and Berlin, was born the last day of October Ifit)'), 

 (old style,) near old Sarum, in Wiltshire. His falhe.r 

 distinguished himself very hononrablv, in the time of the 

 Hevolution, by raising and supporlintr- at his own expense, 

 a company of infantry to assist king William, and ex- 

 pended in it the sum of 2000l., no part of which was ever 

 Reimbursed him by goyerument. 



The son, aftef receiving that kind of education which was 

 necessary to t^ualify him for the university, was entered at 

 Christ's college, Oxford, where he applied with great ar- 

 ■<iour, not only to the study of phvsic, for which he was in- 

 tended, but also to many other sciences : he had, in parti- 

 cular, a strong partiality for o])tics, and was rarely without 

 sir Isaac Newton's treatise on that subject in h.is pocket, 

 'i'his will not surprise us much, when we co^nslder how ne- 

 cessary a know ledge of this science is to the one Cor the 

 advanceiiieut of which he had so remarkable a nredilectioni| 

 Not contented with acquiring the theory of a^tronoinv, he 

 made himself also a proiicient in the practical part, even 

 while he Wits at college; and frequeutly anmsed himself 

 O 4 with 



