By the nut Q it may be moved from eaft to weft;, it may be
elevated or depreffed by the nut R.v J
d e, two fcrews to faften the microfcope to a window-fiiutter.
The box for opake objefts is reprefented at H I K L • it con
tains a plane mirror M, for reflefting the light that « ’ receives
from the large lens to the objeft, and thereby illuminating it ■ S
is a fcrew to adjuft this mirror, or place it at a proper angle for
reflefhng the light.
V X two tubes o f brafs, one Hiding within the other, the extenor
one m the box H I K L ; thefe carry the magnifying lenfes :
the interior tube is fometimes taken out, and the exterior one is
then ufed by itfelf. Part o f this tube may be feen in the plate
within the box H I K L . *
A t H there is a brafs plate, the back part o f which is fixed to
the hollow tube h, m which there is a fpiral wire, which keeps
the plate always bearing againft the fide H o f the brafs box H I
K L. The Aiders, with the opake objefts, pafs between this
plate and the fide o f the b o x ; to put them there, the plate is to
be drawn back by means o f the nut g.
i k, a door to one fide o f the opake box.
The foregoing pieces conftitute the feveral parts necefihry for
viewing opake objeas. I fhall now proceed to defcribe the Angle
microfcope, which is ufed for tranfparent objeas : but in order
to examine thefe, the box H I K L mull be firil removed, and in
it’s
M i c ros cop i ca l E ssays. 95
it’s place we mull infert the tube Y of the fingle microfcope that
we are now going to defcribe.
Fig. 2, Plate V. reprefents a large tooth and pinion microfcope
; at m, within the body o f this microfcope, are two thin
plates, that are to be feparated, in order to let the ivory Aiders
pafs between them ; they are prefled together by a fpiral fpring,
which bears up the under plate, and forces it againft the upper
one.
The Aider, Fig. 3, that contains the magnifiers, fits into the
hole n ; any o f the magnifiers may be placed before the objeft,
by moving the aforefaid Aider : when the magnifier is at the center
o f the hole P, a Snail fpring falls into one o f the notches
which is on the fide o f the Aider, Fig. 3.
Under the plate m are placed two lenfes, for enlarging the field
of view on the fcreen: the fmaller o f the two is fixed on a piece
o f brafs, and is neareft the plate m ; this is to be taken out, when
the magnifiers, No. 4, 5, or 6, are ufed, or when the megalafcope
lens, Fig. 4, is ufed; but is to be replaced for No. 1, 2, 3.
This microfcope is adjufted to the focus, by turning the milled
nut O.
T o use the Solar Microscope.
Make a round hole in the window-lhutter, a little larger tlfan
the circle a b c ; pafs the mirror C N P through this hole, and
apply the fquare plate to the fiiutter ; then mark with a pencil
the