?36 TURNING. 
which locksmiths use to bore keys ; and be- 
ginning wij;h a small one, ancl afterwards 
taking larger ones, the hole is to be made as 
wide and deep as necessary ; great care must 
be taken to hold the borers firm to the rest, 
otherwise there is danger of not bori’ng the 
hole straight. The borer must be withdrawn 
from time to time to oil it and to clean 
the hole. Since it is difficult to make a 
hole quite round with borers alone, it is ne- 
cessary to have also an instrument a good 
deal smaller than the hole, one of the sides 
of which is sharp, very well tempered, and a 
little hollow in the middle. This instrument 
being fixed in a petty long handle, is to be 
applied with steadiness to the inner surface of 
the hole, and it will entirely remove every 
inequality that may have been there before 
its application. 
For turning ovals, a lathe of somewhat a 
different construction is used. The axis or 
spindle, having on it the pulley over which 
tjie band-cord passes for turning the lathe, is 
fixed between the two puppets so as to turn 
round easily ; one end of it passes through 
one of the puppets, and to it is firmly fixed a 
circular plate of brass, so that it turns round 
along with the spindle. Upon this plate two 
brazen segments of circles are fastened, the 
circumferences of which correspond to the 
circumference of the plate ; their chords are 
parallel, and equally distant from the centre 
of the plate, so that they leave a distance be- 
tween them. They have a groove in each 
of them ; in these grooves another plate is 
placed, which exactly , fills up the space be- 
tween the two grooves, but is shorter than 
the diameter of the larger circular plate on 
which it is laid. This plate is made to slide 
in the grooves. To its centre is annexed a 
short spindle, on which the piece of wood to 
be turned is fixed. When the lathe is set 
a going, the circular plate moves round, and 
carries the piece along with it ; the plate of 
brass on which the piece is fixed, being fixed 
loosely in the grooves already described, 
slides down a little every time that the 
grooves become perpendicular to the floor 
(and there are particular contrivances to 
prevent it from sliding down too far) ; and 
by these two motions combined (the circular 
one of the large plate, and the straight one of 
the small), the circumference of the piece of 
wood to be turned necessarily describes an 
oval ; and gouges or other tools being ap- 
plied in the usual manner, supported on the 
jest, it is cut into an oval accordingly. The 
small plate may be made to slide either more 
or less in the grooves ; and by this contriv- 
ance the transverse diameter of the oval, or 
rather ellipse, may be made longer or shorter 
at pleasure. Another, and still simpler me- 
thod if possible, of turning ovals, is this : Take 
two ovals of metal, exactly of the size of the 
oval which you intend to make ; fix them 
firmly on the spindle of the lathe, so as to 
turn round with it ; fix between them the 
wood to be turned, and then it is easy, by the 
help of chisels and other tools, to cut it, as 
the lathe goes, into exactly the figure of the 
external ovals. Or an oval may be formed 
by placing the wood, or whatever is to re- 
ceive that shape, obliquely on the lathe. 
There are several other ingenious methods 
of turning, but our bounds do not permit us 
40 enter upon them. We shall therefore 
•onclude this article, with a number of 
receipts, which every turner ought (o 
know. 
1. The method of moulding boxes both of 
shell and horn. In the lirst place, form a 
proper mould, which must consist of two 
pieces, viz. of a circle about half an inch 
thick, which should slope a little in order to 
dr&w out the moulded shell the more easily ; 
and a ring lilted to the outside of the circle, 
so that both together make the shape of a 
box. These two pieces being adjusted, it is 
necessary to round the shell to be moulded 
of such a size, that when moulded, it will be 
a little higher than the ring of the mould, 
that there may be 110 deficiency. The mould 
is then to be put into a press 011 a plate of 
iron, exactly under the screw of the press ; 
put then the shell upon the circle, of the 
mould, so that its centre also is exactly op- 
posite to the screw of the press : then take a 
piece of wood formed into a truncated coue, 
and not so thick as the diameter of the circle 
of the mould, nor so deep as the ring ; then 
put a plate of iron above the cone, and screw 
down the press gently and cautiously till the 
whole is well fixed ; then plunge the whole 
into a cauldron of boiling water placed above 
a fire. In eight or ten minutes the shell or 
horn will begin to soften; screw the press a 
little firmer that the wooden cone may sink 
into the softened shell : repeat this from lime 
to time till the cone is quite sunk in the 
mould ; then take out the press and plunge 
it into cold water. When it is cold, take 
the box now formed out of the mould, and 
put into the inside of it a new mould of tin 
exactly of the form you wish the inside of the 
box to be ; do the same with the outside, 
put it again into the press, and plunge it 
into boiling water; screw the press gradually 
till the box is fashioned as you desire. 
2. Method of preparing green wood so that 
it will not split in the turning. Having cut 
your wood into pieces of a proper size, put 
it into a vessel full of a ley made with wood 
ashes. Boil it there about an hour; then, 
taking the cauldron off the fire, allow the ley 
to cool ; then take out the wood and dry it 
in the shade. 
3. Method of giving an ebony-black to hard 
and fine woods. After forming the wood 
into the destined figure, rub it with aqua 
fortis a little diluted. Small threads of wood 
will rise in the drying, which you will rub 
off with pumice-stone. Repeat this process 
again, and then rub the wood with the fol- 
lowing composition : Put into a glazed 
earthen vessel a pint of strong vinegar, two 
ounces of fine iron-filings, and half a pound 
of pounded galls, and allow them to infuse 
for three or four hours on hot cinders. At 
the end of this time augment the fire, and 
pour into the vessel four ounces of copperas 
(sulphat of iron), and a chopin of water hav- 
ing half an ounce of borax and as much in- 
digo dissolved in it ; and make the whole 
boil till a froth rises. Rub several layers of 
this upon your wood ; and, when it is dry, 
polish it with leather on which you have put 
a little tripoli. 
4. Method of giving to plum-tree the co- 
lour of Brazil wood. Slack lime with urine, 
and bedaub the wood over with it while it is 
hot ; allow it to dry ; then take off the coat 
of lime, and rub it with chamois-skin well 
oiled. Or, steep your wood in water having 
a quantity of alum dissolved in it, five or 
six hours, kept lukewarm during a night; and 
when it is dry, rub it, as before directed, with 
chamois-skin well oiled. 
5. Method of giving a fine black colour to 
wood. Steep your wood for two or three 
days in lukewarm water in which a little 
alum has been dissolved; then put a handful 
of logwood, cut small, into a pint of water, 
and boil it down to less than half a pint. If 
you then add a little indigo*, the colour will 
be more beautiful. Spread a layer of this 
liquor quite hot on your wood with a pencil, 
which will give it a violet-colour. When it 
is dry, spread on another layer ; dry it again, 
and give it a third ; then boil verdegns at 
discretion in its ovfn vinegar, and spread a 
layer of it on your wood ; when it is dry, rub 
it with a brush, and then with oiled chamois- 
skin. This gives a fine black, and imitates 
perfectly the colour of ebony. 
6. Method of cleaning and whitening bones 
before using them. Having taken olf with a 
saw the useless ends of the bones, make a 
strong ley of ashes and quick-lime* and into 
a pailful of this ley put four ounces of alum„ 
and boil the bones in it for an hour ; then 
take the vessel containing the ley ofi'the fire 
and iet it cool ; then take out the bones and 
dry them in the shade. 
7. Method of soldering shells. Clean the 
two sides of the shells which you wish to join 
together ; then, having joined them, wrap 
them up in linen folded double and well 
moistened ; then heat two plates of iron 
pretty hot, that they may keep their heat for 
some time ; and putting your shells rolled up 
between them under a press, which you must 
screw very tight, leave them there till the 
whole is cold, and they will be soldered. If 
you do not succeed the first time, repeat the 
process. 
8. Method of moulding shells. Put six 
pints of water into a kettle ; add to it an 
ounce of olive or other oil ; make the water 
boil ; then put in your shell, and it will grow 
soft. Take it out, and put if into a mould 
under a press, and it will take the figure you 
want. This must be done quickly ; for if 
the shell cools ever so little, the process will 
fail. It will not require much pressure. 
9. Method of tinging bones and ivory red 
Boil shavings of scarlet cloth in water* 
When it begins to boil, throw in a quarter of 
a pound of ashes made from the dregs of 
wine, which will extract the colour: 'then 
throw in a little rock alum to clear it, and 
pass the water through a linen cloth. Steep 
your ivory or bone in aqua fortis, and put it 
into the water. If you wish to leave white 
spots, cover the places destined for them 
with wax. 
10. To tinge ivory black. Steep the ivory 
during five or six days in water of galls, with 
ashes made with dried dregs of wine and 
arsenic ; then give it two or three layers of 
the same black with which plum-tree is black- 
ened in order to imitate ebony. Or dissolve 
silver in aqua fortis, and put into it a little 
rose water. Rub the ivory with this, and al- 
low it to dry in the sun. 
11. Method of hardening wood to make 
pulleys. After finishing the pulley, boil it 
seven or eight minutes in olive-oil, and it 
will become as hard as copper. 
12. To make Chinese varnish. Take ef 
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