C ) 
my Eyes ; to be farther fatisfied, I removed the Water 
and found, that whether I held the Needle Perpendicular 
Horizontal, or inclined to all thefe poftures it was in- 
verted, I then made' many holes, and in every one I 
fawthe inverted Pifture of the Needle; the nearer the 
Needles was to the Holes, 'twas fo much the more Mag- 
nified, but lefs diftindl, if the Needles point were ib 
held, as that its Image were near the edge of the Hole, 
its point feemed Crooked : So that it feems thefe fmall 
Holes, or fomewhat in them, performs the Effedls of 
a Concave Speculum, and fol take leave to call them 
aereal Speculums but how the Rays of Light can 
be Refleded, before they come to a Medium of a 
different Denfitie, or how, or by what means the Air 
remains in fmall Holes, in a Concave Spherical Form, 
I muft leave to the Confideration of the Learned to 
Determine, 
V V t 
IV. Of 
