by straight strokes across th^ ,j>Qli$lier, .^a the, tiioijfR'efs^ 

 di^aieter of thq, xilljp^e,, toy traversQ t^iat pavt. of it, whicli 

 circumscribes the circle; 9.nclj by such strokes made twice, 

 djiifectly iu tliat: diameter, ^pd ofhenev P^bljcLuely, in e^ch 

 rpt^tipji, <^f, tjie.miji^fQr^^^as, the operator moves round the 

 polisher, during the process, the, ;reg>,iiar shape of the po- 

 lisher is preserved. Bvit it is easy to conceive,, that the 

 same efiects would follow, though the poljshiqg >yerp con- 

 ductedj, , nQf by straight strokes across, . but by. round, 

 stj-qkes,.j^n,;a;spiyai direction, as above^i>ien,tioned. And 

 I ani doubtful, to which of these motio.is the ,preferqnce 

 siioujld be given; or whether they ought not to be in- 

 t^t'changeably used, to produce tlie most elaborate forni 

 i«^ the. ^.wirroE;:a^,, also,, Avh^ther , thi? methpd, of Mr. Ed- 

 \y:^dsj^,:i^ bqt,ter th^n, the former, by JNIr. Mudge, above 

 described, (I Spt; J .4)9ive beeit deprived ;pf leisure an4 PPr 

 poftiu^ity (by the. war, and ipublic troubles, during the 

 Frencl} invasion and the rebellion; in which, most of my 

 iri^truments, for such purposes, were lost, in the phnider 

 and destruction of my house,) to prosecute the experi- 

 mentS;* Svhidh nl^^t h^'i^e ^hablQcJ me' to '^peaik with more 

 precision; aM which I would have done, from the dC' 

 sir« I had, to contribute to the i>erfection of jso. jnoble 

 an' instrMnent as the reflecting telescope. :,(•■:■,. 



L'kiiow, feat both' methods will, injudicious practice, 

 produce the desired .eiiect; but thia .efiect will be Umit- 

 ed-i -in degtee'df "perfection, and sometimes frustrated, 

 Wneii the causes and circunistanqes, that operate ia it, 



