744 ANNUAL REGISTER, 1805. 



French philosopher, \^-ith the title 

 conferred on him of correspondent 

 of the Academy of Sciences, could 

 not fail to prove higlily gratifying 

 to his youthful ■ pnity. 



After Boscovich had completed 

 ihe usual course of philosophy, he 

 ■was obliged, by the rules oi the in- 

 stitution, to teach grammar and the 

 classics ; but he never lost sisjht of 

 his favourite studies, and be Mas in- 

 vited by his mathematical master to 

 defend annual theses, and deliver 

 dissertations on such subjects as oc- 

 casion suggested. These being print- 

 ed in succession, extended farther 

 his reputation. The first appeared 

 in 1736, and contained a theory of 

 the solar spots, very similar to that 

 "ivhich was afterwards so ingenious- 

 ly supported by professor Wilson 

 of Glasgow. It supposes the sun 

 to have two atmospheres, the lower 

 being dense, and sometimes sprink led 

 with clouds ; the upper rare, and 

 subject to variation of height. Next 

 year produced two dissertations ; 

 one on the transit of Mercury, and 

 another on a remarkable aurora bo- 

 realis. 



Five years had Boscovich spent 

 in the drudgery of teaching latin. 

 and three more were consumed in 

 the unprofitable study of scholastic 

 theology, wl:en, by a very singular 

 indulgence, he was exempted by iiis 

 superiors from the fourth year's at- 

 tendance, and permitted to rclin- 

 quish that dark and thorny path, 

 and thenceforth employ his talents 

 ill exploring nature's wide domain. 

 His situation now, as supernumera- 

 ry prefect of the Roman college, 

 was entirely suited to his taste. To 

 communicate mathematical instruc- 

 tion was to him a delightful (ask ; 

 and he prepared, for the use of his 

 pupils, a short system of geometry. 



which comprised all the capital 

 truths of that science, in fourteen 

 propositions. In the selection of 

 the materials, in their disposition 

 and arrangement, he exhibited the 

 clearness, the precisi9n, and noble 

 elegance, formed a.ftet the model of 

 the ancients. , He composed tha 

 elements of trigonometry with the 

 same purity of taste. But the Ca- 

 pital part of the system, his the- 

 ory of the conic sections, was 

 reared by repeated efi'orts, and at 

 distant intervals, and was not pub- 

 lished until the year 175.5. Bo«co- 

 vicli considered these curves as de- 

 scribed ill piano, and assumed, for 

 his generic definition, the beautiful 

 property of the directrix, which is 

 common to them all, the parabola 

 being only its simplest case. In the 

 eclipse, tiie ratio of a line drawn 

 from any point to either of the 

 fopi, is to a perpendicular front 

 tlie same point to the directrix, 

 in the ratio of a less to a greater ; 

 in the hyperbola, it is that of a 

 greater to a loss. But the author 

 did not stop here; he likewise in- 

 vestigated the properties derived im- 

 mediately from the section of the 

 cone. I-le supposed it cut by a 

 moveable plane, and showed how 

 the several curves would thence be 

 successively produced. The same 

 lumii.'ous idea he transferred to the 

 cylinder, the spheroids. His ima- 

 gination loved to contemplate the 

 tine nnitation and transition of ma- 

 tjiematical figures, and to trace the 

 series of successive, yet apparently 

 connected changes, which have sug- 

 gested the law of continuity. On 

 that metaphysical principle, as elu- 

 cidated by the transformation of 

 gpon;etr:ral loci, he gave an cx- 

 fiuisite dissertation Other disser- 

 tations, remarkable for their inge- 



Buitjj 



