Part IV. Natural Fbilofifby. 
but alfo to keep the Flame of equal ftrength, for all fuch 
purpofes as require it. 
The MODEL of an EYE. In which the Humours are 
reprefented by Glaifes of an anfwerable Figure. 
A BURNING-GL ASS, about half a foot in Diametre. 
A HOLLOW BURNING-GLASS. That is to fay, two 
thin concave Glaifes fet together, and fo to be fill'd up with 
water when it is us'd. About the fame bignefs as the 
former i but burneth not altogether fo ftrongly .Contrived 
and given by Dr. John Wilkins late Bifliop of Chefler. 
A Large MICROSCOPE, with three Glaffes, andfeve- 
ral Screws to fit it for all manner of pofitions. It magni- 
fies the Area of the Objecl: to above a hundred times the ex- 
tent thereof to the bare Eye. 
A Lcfler MICROSCOPE, fomewhat more managable 
than the former. 
The advantage of one with more Glaifes, is that it takes 
in a bigger Objecl:, or a greater part of it. Of one with 
a fingle Glafs, that it Ihews the Objecl; clearer. So that to 
have a diitinct reprefentation of it, 'tis convenient to make 
ufe of both. Of the latter kind, I have feen feveral made 
by Mr. John Mailing in this City, not only with melted, 
but with Ground-Glaifes fo very fmall, that one of thefe 
Ground-Gaffes being weighed in the Ajf ay-Scales in the 
Tower , was found not above the fourfcorth part of a 
Grain. The Diametre or Chord »V h part of an inch. 
Another, fo fmall, that thofe Scales were not nice enough 
to weigh it. The Chord hereof to that of the former, 
is as two to three. Thefe are the cleareft and befl that ever 
Ifaw. 
An OTOCOUSTICK,or Inftrument to help the hearing, 
made of Ivory. In lhape like a Funnel, faving that the Nofe 
is bended for the more convenient application to the Ear, 
and reception of the found. Given likewife by Biihop 
Wilkins. 
Another of Copper, funnePd at one end, as the former, 
and alfo belly cl in the middle. 
A Third of Tin, of a Conick. Figure, and with a Cochlea 
within it. The bed of all the three, is the firft. 
A Pair of HYDROSTATICK Scales. Ufed , amongft 
other purpofes,to examine the fpecifick Gravity of Bodies. 
A 
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