Ci>5 )'

XXX. Paper: (of les: General Vse) Omitted.

j w T"NR. Hock. having (in his Micragraphia) deleribed a new Engine for Grind- optn\ Ghsses,

I J ing Optick. Glaste: of verygreat lengths, M .Auqout (in a (mali Frencb h J* Tur "Traft) Objects scveral Difficulties to tbis Engine it seif-: But however, he ^’ 5 V .thinks it impracticable to make any Glaffes of above 300 or 400 Foot atmoib, (and fears that neither Matter nor Art will-go even fo far) which willbe very far from showing us Piant: or Animal: in the Moon j and then pro-poles Remedies to some of the Inconveniences of the Turn. To all this,

Dr. Hook_ here Replies He Answcrs the Objections, and Rejects the proposed ibid. p.Expedients.

Z. Carlo Ant. Mancini having, in his Occbiale ali ’ Occbio, deleribed a v P on * ;

particular way for making Convex-Glasies upon a Plain, his Method is here"' 42, ?,8 3 8 *Transtated from the Italiau into F.ngUJh. But ’tis addcd, That though thecontrivance be Ingenious, yet it is conceiv’d by Skilful Artists, that it will bevery disticult to put it into Practice.

XXXI. Account: of Bookj, Omitted.

I. p Hysico-Ma thesis dt Lumine, Coloribus, fi? Iride, fi?c. Autb. Frano Maria n . p, 3048,X” Grimaldo, S.J. Bononiae 1665. ->r 4:0.

z. Cogitatione: Physico-Mecbanic.c dc Natura Visioni:. Autb- Jo. Ott. Scbapbtsta rr. 71.. p. ilLz.Helvetio. Heidelberg« 1670. in rtto.

5' Synopsi: Optica. Autb. Honorato Fabri. Soc. fisu. Lugduni 1667. inn. 32. p.6H,Quarto. \

4. L 1 Occbiale ais Occhie, ovcr.o Dioptrien Frattica, dei Carlo Ant. Mancini, in n . 42, p. 837;Bologna 1660. in Quarto .

5". Lcftionc: I 8 Cantabrigix in Scholl: publici: habita: in tpuibu: Opticorum n. 75. p,zzt3,Phicnomenton Genuina: Ratione: investigantur, fi? exponuntur, ab Ilaaco Barrow.

Lond. 1669. in Quarto.

6. La Dioptritjue Oculaire, par le Pere Cherubin d' Orleans, Capucin. n. 78. p, 304=.A Paris 1671. in Folio.

7. Christiani Hugenii Astroscopia Compendiaria, Tubi Optici molimine Libe~ n ‘ 161» p 663,rata : Or, The Delcription of an Aerial Telcfcopc. Hague, 1684. in Quarto .

8. A Treatile of Dioptricks. By Hili. Molyneux Elq; F. R. S. in Quarto, n. 205. f . 9 c 7 .Qy. Catoptric.c fi? Dioptrien: Elementa. Auftore Davide Gregorio» D. M. n, 21?. p. na.

Oxon. r6yy. inOftavo,

CH A p;