(^03) 
mentioned from him in ISlumb, 4/^. 673 o£ thtfcTranJaUi- 
mis. 
Prepare ( (aith h ) two GlafTes, the one exa5:Iy flat on both 
fides, the other flat on the one fide, and convex on theother^ 
of what Sphere you plcafe. Let the flat Glafs be a httle broa- 
der than the other. Then let there be made a Cell or Ring: 
of BrafSj very exactly turned, into which thefe two GlaflTe^ 
may be fo faftned with Cement, that the plain furfaces of 
them may lye exadly paralel!, and chat the Convex-fide of the 
Plano-convex-Glafs may lye inward ; but ^o^ as not to touch 
the flat of the other Glafs. 1 hefe being cemented into the 
Ring very clofely about the edges, by a imal! hole in the fide 
of the Brafs-ring or Cell, fill the interpofed fpace between 
thefe two with §yl of Turpentine ^ Spirit ^ Wine, Salim 
Liquors, then flop the hole with a fcrew : and accord- 
ing to the diflering refra<?lion of the interpofed Lfquors^, 
fo fliall the Focus oi this coinpound Glafs be longer or flior^ 
ter. 
But this ( adds the Fropofir ) I woiild only have looK't upon.,- 
as'one inftance of many ( for there-tnay be others^ of the 
i^^^W/Vj of making a Glafs, ground in a fmaller Sphere, to 
Gonftitute a Tclefcope of a much greater length : . Though • 
( not to raife too great exfpe^tation ) I muft add 5 That of^ 
Spherical objedl glaffes, thofeare the beft, which are made of 
the greatcfl Sphere, and whofe fubfl:anc@ hath the greateftc 
refrad:.Lon. ^ • . ' 
Obfervatiom 
About SKmng Worms in Ojfters^^ 
Thefe Obfervations occur in the French jo tm^ a I of April i 
%.666, in two letters , written by M. Awx^ut to Dela^ 
F/eye 5 whereof the fubftance may be reduced to the following: 
particularSo-.. 
That M. Uela Voje having oi'bferved, as he tbongHt5\ 
