S, a camel’s hair pencil to brufh the dull off the glafles; the
upper part o f the quill is fcooped out, to take up a drop o f any
fluid, and place it on either o f the glaffes for examination.
T , an inftrument for cutting thin tranfverfe fe&ions o f wood.
It confifts o f a wooden bafe, which fupports four brafs pillars; on
the top of the pillars is placed a flat piece of brafs, near the middle
of which there is a triangular hole.
A fharp knife, which moves in a diagonal direflion, is fixed on.
the upper fide o f the afore-mentioned plate, and in fuch a man-
ner, that the edge always coincides with the furface thereof.
The knife is moved backwards and forwards by means of the
handle a. The piece o f wood is placed in the triangular trough,
which is under the brafs plate, and is to be kept fteady therein,
by a milled fcrew which is fitted to the trough ; the wood is to
be preffed forward fox cutting by the micrometer fcrew h.
The pieces of wood fhould be applied to this inffrument immediately
on being taken out o f the ground, or elfe they fhould.
be foaked for fome time in water, to foftcn them fo that they may
not hurt the edge o f the knife;
When the edge of the knife is brought in eontaft with the-
piece of wood, a fmall quantity o f fpirits of wine fhould be poured
on the furface o f the wood,' to prevent it’s curling u p ; it will
alfo make it adhere to the knife, from which it may be removed
by prefling a piece of blotting-paper on it,.
Y is.
Y is an appendage to the cutting engine, which is to be ufed
inflead o f the micrometer fcrew, being preferred by fome practitioners
to it. It is placed over the triangular hole, and kept flat
down upon the furface of the brafs plate, while the piece o f wood
is prefled againft a circular piece o f Brafs which is on the under
fide o f it.
This circular piece of brafs is fixed1 to a fcrew, by which- it s
difiance from the flat plate on which the knife moves may be
regulated.
Z, an ivory box, containing at one end fpare talc for the ivory
Aiders, and at the other fpare rings, for prefling the talcs together,
and confining them to? the Aider,.
C H A P ,