( 354 ) 
the Frame of the Micr.ofcope, it may be about half 
one eighth part of an Inch in thicknefs,' at A. there 
is a (mall hole, near one thirtieth of an Inch Diameter, 
this fervefor the Aperture ot the Water, being in the 
Center of a larger Spherical Cavity, about one eighth 
of an Inch Diameter, and in deptxh, fomewhat more 
than hah' the thicknefs of the Brafs ; oppofite to this, 
at the other fide, there is an other Concave but half 
the breadth of the former ; which is fo deep, as to 
reduce the Circumferertce of the fmali Hole in the Cen- 
ter, to almoft a Iharp edge ; in theft Cavities the Wa- 
ter is to be placed, being taken upon a Pin or large 
Needle, and conveyed into them, till there be formed 
a double Convex Lens of Water ; which, by the 
Concaves being of different Diameters, will be equi- 
volent to a dpuble Convex, of unequal Convexeties ; 
by this means I find the Objeftis rendred more diftind: 
than by a Piano Convex of Water, or by a double 
one , formed on the plain Surface of the Metal ; be* 
fide the Water is now better fecured in its Spherical 
Form. 
C D. E. is the fiipporter, whereon to place the Ob- 
ject if it be Water in the Hole G. if a folid Objeft 
on the Point this is fixed to the Frame of the Mi- 
crofccpe, by the Screw E. where 'tis bent upwards, 
that its upper part may ftand at a diftance from the 
Frame; 'tis moveable on the Skrew, as a Center to 
the end, that either the Hole C. or tte Point F, 
may be expoftd before the Microfcope and tha^t the 
Objed; may be brought to, and fixed in its Focus : 
There^isjinother Skrew, about half an Inch in length, 
which goes through the round Plate into the Frame of 
'the Microfcope^. E, the Skrew and Plate taking hold 
of the Supporter about £>riA^here t[iere is a flic fome- 
what larger then the Diameter of the Skrew, which is 
re^uifite 
