92 M i c r o sc 6-pic al E s s a y s ..
A pair o f forceps.
A fieel wire, with a pair o f nippers at one end, and a point at
the other.,
Afmall ivory cylinder, to fit on the pointed' end o f the afore*
faid nippers»
A convex lens, moveable in a brals femicirele; this is affixed to>
a long brafs pin, which fits into a hole on the ftage..
I f the reader wants a more particular defcription o f any ©f the.
articles o f this apparatus, he will find it at the latter end of this:
chapter.,
A D escription of the improved S olar Microscope,.
WHICH i s CONSTRUCTED TO'EXHIBIT TRANSPARENT :AND;
o pak e . O bjects, Fig. r, Plate V..
The folar microfcope is, generally fuppofed to afford the moft
entertainment, on account o f the wonderful extent o f it’s magnifying
power, and the eafe with which feveral perfons may view
each fingle object at the fame time; The ufe o f it was,,-however,,
confined for many years only to tranfparent objefts.. About the
year 1774, Mr. B. Martin fo far improved this iiffirument, as to
render it applicable to opake, as well as to tranfparent objects,,
exhibiting the magnified image o f either kind on a large fcreen.,
Speaking o f it himfelf, he fays, “ With this inftrament all opake
objefts, whether o f the animal, vegetable, or- mineral kingdom,
may be exhibited in great perfection, in all their native beauty ;-
the
w-
M i c r o s c o p i c a l E s s a y s . 93
the lights and {hades, the prominencies and cavities, and all the
varieties of different hues, tints, and colours, heightened by the’
refleftion o f the folar rays cOndenfed upon them.” Tranfparent
objefts are alfo ftewn with greater perfeftion than in the common
folar microfcope.
pjg I( plate V . reprefents the folar opake microfcope,
mounted for exhibiting opake objefts.
Fig. 2 is the fingle tooth and pinion microfcope, which is
mfed for ffiewing tranfparent objefts ; the cylindrical tube Y thereo
f being made to fit into the tube F E, Fig. M
Fig. 3, the Aider which contains the magnifiers; it fits into a
dove-tail which is at the upper part of the microfcope, Fig. 2.
A B C D E F , Fig. 1, reprefents the body o f the folar microfcope;
one part thereof, A BCD, is conical, the other, C D E F ,
is cylindrical. The cylindrical part receives the tube G of the
opake box, or the tube Y of the fingle microfcope, Frg. 2.
A t the large end A B o f the conical part, there is a lens to re-
eeive the rays from the mirror, and refraft them towards the box
H I K L .
N O P is a brafs frame, which is fixed to the moveable circular
plate a bc ; in this frame there is a plane mirror, to re e
folar rays on the afore-mentioned lens.
This mirror may be moved into the moft convenient peffiion
for reflefting the light, by means of the nuts Q an ^