f 2258 ) 
An Accompt of fome Bookj* 
I. LeBiones id^ Csintzbngl^ in Scholis publicis babita^ inquihut 
OPTlCOI{VMPhcenomenci>v Genuince rationes invejligantur ^ ex^ 
fonuntur^ Ilaaco BarroW, Coll. S.Tnn^Secio^ Mathef Pro- 
/^/♦LpcafianOjC^ Soc. Reg\3Z Sodali. Londini, 1669. in 
Impenfis Joh.Dunfmotc ad In/gneJ^ofi & Corona^ in Cameterio 
D. Pauli. 
ABrief fummary of thefe Optic^LeBures the Excellent Au- 
thor doth himfelf deliver in an Epiftle to a Friend, who 
defircdfuch an one from hirn, when he faith, that in them he 
cndeavoureth to promote that part of Optickf, which he un- 
dertakes to treat upon , firft by explaining and eftablifliing its 
Principles > then by deriving from them fome ufeful Con-* 
fecStarics^ ferving to the explication of the Phcenomena : in the 
mean while att^mptingto correft fome common errours, and 
tp iupply fome principal defeats therein. 
Towards thefe purpofes^he firft examineththe received Hy* 
fothefej of thisScicnce^fliewing^how they fliould beanderftood^ 
and how far admitted ; afligning alfo fome Phyfical caufes of 
them^ (in the perf ormance whereof he declares himfelf not to, 
confide much, but only requires the Hypothefes themfelves^. as 
not dilagreeableto Reafon^andvery congruous to Experiencej 
to be admitted.) 
Having firft (etled the Hypothefes firft draweth from them 
fome general CorollarieSj partly before acknowledged by o- 
thers, and partly obferved by himfelf , all confirmed by his 
©wn d^emonftrations,. 
Then proceeding to more Special matters 5 he profecutes 
Catoptric}^ zxidLDioptricks^ both P/^?>i and Spheric-al^ 
And {lightly pa(5ng over F/<^?>2 C^^o/>^r?V;^i" (as eafy and com- 
monly treated on, truly enough^) he more largely infifts upon 
Spherical CatBptricks, propounding fuch Theorems , whereby 
the Interfecftions, and the Limits of Reflefted rays are decla^ 
red, and together the Appearing places,, or images of points 
radiating both from a great (and.as it were, immenfe) diftance^ 
and from a diftance fenfibly near, are determined^ both in re- 
• fpeiSt of an eye placed i« the Axis of the radiation, and in re* 
Jpe(3: to one ^hc^A wiibmp t^at Axis any where 5 the which 
garticularr 
