XXX 
The Mkrofcope explained. 
on the back of this fpeculum a male fcrew L, Is made to 
fit the brafs ring I, which may be fcrewed into the faid 
ring at pleafure. 
Four of thefe concave fpecula of different depths, 
are fitted to four glades of different magnifying powers, 
to be ufed as objedts to be examined may require. The 
greateft magnifiers have the leaf! apertures. 
M, a round objedt plate, one fide white, and the 
other black, intended to render objedts the more vifible, 
by placing them, if black, upon the white, and if white, 
on the black fide. A fteel fpring N, turns down on each 
fide to make any object faft; and ifluing from the ob¬ 
ject plate is a hollow pipe to fcrew it on the needle’s 
point G. 
O, a fmall box of brafs, with a glafs on each fide con¬ 
trived to confine any living objedt, in order to examine' 
It j this alfo has a pipe to fcrew upon the end of the 
needle at G. 
P, a turned handle of ivory to fcrew into the inftru- 
ment when it is made ufe of. 
Q: a pair of plyers to take up any objedt, or manage it 
with conveniency. 
R, a foft hair brufti to clean the glalfes or fpecula. 
When you would view any objedt, fcrew the fpeculum 
with the magnifier you intend to ufe, into the brafs ring 
I, place your objedt either on the needle G, in the plyers 
H, on the objedt plate M, or in the brafs hollow box 
o, as may be moft convenient according to the nature 
and condition of it: then holding up your infirument by 
the handle P, look againft the light through the magni¬ 
fying lens, and by means of the nut D, together with 
the motion of the needle, by managing its lower end, 
the objedt may be turned about, raided, or deprefled. 
Brought nearer the glafs, or put farther from it, till you 
bit the true focal difiance, and the light be feen refledted 
fronj 
