pieces of slender wood or ivory, and has this advantage, that the
workman can easily make it for himself. It should be constructed
of very hard, well-seasoned wood. The foot, E, must be in breadth
exactly the size of the aperture in the bed of the lathe, and is
kept quite steady by a bit of wood thrust through it underneath the
lathe. Into this collar, fit many pieces of wood with different
sized holes bored through them, (all exactly in a line with the
axis of the mandrel,) so as to admit large or small pieces of work,
the sides being grooved, and the supports sawn to correspond: they
all slide in with great ease, and are kept quite steady by an iron
pin which runs through the top. The fig. G, shows the collar, with
one of the supports slipped in, the other sliding upon it; H is the
collar, showing the groove, and L L are two supports that fit into
it. The _middle_ of the apertures of these supports, whether large or
small, must always be exactly on a line with the axis of the mandrel,
therefore, after they are bored quite true on the lathe, they are
sawn exactly across the hole. This is a very useful addition to the
lathe, not only as a support when boring holes, but also to be used
with the right hand puppet, to give strength to any long slender
piece of work, as a screen-handle or a pen-holder; for, being of
great length, the stress necessary to the proper management of the
tools would be apt to break the wood or ivory, and it is easy to make
one of the ornamental mouldings of a proper size, to enable it to run
smoothly in one of the supports; if too tight, the wheel will not
turn, and if too loose, the work will jerk up and down.
For boring, there are many shaped tools of various sizes; 16, 17, pl.
1, are drawings of the most useful. They have no handles, but at the
smaller end a hole is drilled, to admit the point, J, of the puppet,
G, pl. 1. Having, with one of the turning tools, made an aperture in
the work sufficiently large to allow the boring tool to enter, screw
the puppet, G, firmly to the bed of the lathe, then turn the small
wheel, K, till the point enters the hole in the tool, which must be
steadied by holding it straight and firm with a pair of pincers. Make
the wheel turn rather quickly, and with the left hand keep moving the
left wheel, K, very gently, so as to force the tool into the wood.
After a few turns, stop the lathe, and take out the boring tool, to
get rid of the shavings and dust; move the puppet nearer and begin
again. A little difficulty will be found in making the tool enter the
wood, or _bite_, as it is called, but, by humoring it gently, it will
soon take hold; care must be taken to keep it quite straight, and not
to go too fast, or it will be liable to break. This method of boring
is only used for small hollow tubes, needle-cases, crochet-needles,
handles, and small work.
OF WOODS.
There are many beautiful English woods which are excellent for
turning; beech is very universally used, and it should be cut into
moderate sized pieces and boiled, to render it more durable, and to
make it work smoothly.
Elm and chestnut are also much admired; if the latter be dipped
in alum water, then brushed over with a hot decoction of logwood,
afterwards with one of Brazil wood, it will be made to imitate
mahogany. Green wood should never be used, as it is apt to split; it
should be kept for at least a year before attempting to turn it. Some
persons, if they fear the wood has not been sufficiently seasoned,
cut it up and put it in a vessel filled with a ley made of wood
ashes. In this it must be boiled for an hour, and allowed to remain
in the liquor till quite cold, afterwards it must be dried in the
shade.
Old walnut wood is very beautiful; to improve its colour, it may be
put in the oven, and when worked, polish it with its own oil, very
hot.
Sycamore, when grown in favourable situations, is as white and
nearly as hard as holly; the cherry, yew, laburnum, and pear-tree
woods, are also very beautiful; but though invaluable for plain
turning, they are not hard enough, or of a sufficiently close and
fine grain, to admit of ornamenting them in delicate and minute
patterns. The milling tools are generally employed for them. Of all
English woods, the holly is the whitest, and is rendered still more
so by boiling; it is, when very good, used for inlaying, in imitation
of ivory. Box is the hardest and toughest of our woods; when cut
plank-wise, it is apt to warp, if not well seasoned; but its yellow
colour, if highly polished, is much admired, and it will receive the
most delicate patterns; it is also used as a substitute for ivory.
The foreign woods are those most prized by the ornamental turner,
on account of their hardness, and the beautiful polish which can be
given to them. Cocoas, or the wood of the palm, is much used for all
kinds of ornamental work. It is of a beautiful brown, streaked with
darker veins, and is found in the West Indies.
Ring wood is extremely hard, of a chocolate brown, with black veins;
it is a good wood for turning, and comes from Brazil.
Partridge and leopard woods, tulip and snake woods, are also
frequently used; the latter is of a very deep red, and very hard.
Calamander wood, a tree growing in the island of Ceylon, is very hard
and heavy, and the veins in it most beautifully shaded. The principal
colours are a fine chocolate, sometimes deepening almost into black,
then gradually shading into a cream colour. It is a very hard wood,
and takes a high polish.
African thorn is of a beautiful dark colour, and much prized when it
can be obtained good, which is rarely the case.
Ebony, an exceedingly hard, smooth, foreign wood, is much admired
by turners. The best is a jet black, free from any veins, and
receiving a very high polish. There is some difficulty in keeping
woods to prevent them from warping or cracking. The foreign woods,
particularly, being usually very dry, often open in fissures while
working. The best method of preserving them is to place them in a
cool and rather damp place, and to rub a little oil now and then
over the outsides, to keep them moist. If the wood is sufficiently
large to allow of its being quartered, the danger of its splitting
is much less; but the foreign woods are rarely large, as the trees
are generally very high, but small in circumference. If foreign woods
cannot easily be obtained, box wood and holly may be stained so as
greatly to resemble them. The dying woods to be used must be in
small chips or raspings. When the wood is ordered to be brushed over
several times with the fluid, it should be dried between each time.
If the stain is wished to be very deep, the wood should be boiled in
the stain.
TO STAIN WOOD RED.
Mix two ounces of Brazil wood, and two of potash, in a quart of
water; let them remain in a warm place for some days, stirring them
occasionally. With this boiling liquid, brush over the wood till it
becomes of the requisite colour; then dissolve two ounces of alum in
a quart of water, and, while the wood is wet, brush it over with it.
For a pink or a rose red, use double the quantity of potash.
A YELLOW STAIN.
Steep one ounce of turmeric in a pint of spirits of wine; let it
stand for several days. Brush the wood over with it. A red yellow is
made by adding to the above a little gum tragacanth.
A BLACK STAIN.
Brush the wood with a hot decoction of logwood, then with common ink.
A PURPLE STAIN.
Boil one ounce of logwood and two drachms of Brazil wood in a quart
of water, over a moderate fire. When one-half is evaporated, strain
it, and brush the wood over with it. When dry, brush it over with a
solution composed of a dram of pearl-ash in a pint of water.
A MAHOGANY STAIN.
For a light stain, mix two ounces of madder and one of fustic in a
quart of water, and boil them all together; a darker stain is made by
using half an ounce of logwood in the place of the madder, and then
brushing the wood with a weak solution of potash.
All hard woods are easily polished; first, they are made perfectly
smooth and even, with the turning tools, after which rub them with
sand paper, then with Dutch rushes, which, to prevent their breaking
into small pieces, should be steeped in water. While using these,
make the lathe turn quickly round, sometimes one way, sometimes the
other, to prevent any unevenness, and keep moving the sand paper, &c.
&c., or the edges are apt to cut lines. When this is done, and the
work looks smooth, rub over it a drop or two of olive oil, wipe it
clean with its own shavings, take it off the lathe, and brush it with
a very hard brush, the same as those used for blacking leather.
As it is impossible to turn well unless your tools are in good
order, great care must be taken to keep them very sharp. If a bit
of the steel splits away, as is frequently the case in turning hard
woods, grind it down till it becomes even again, then rub it on the
Turkey stone, with a little olive oil, till the edge is so sharp that
you cannot see it; for the gouges and hollow tools, thick Turkey
stones, rounded at the edges, are sold, which enter into the groove,
and the outer edges are rubbed on the flat stone.
As soon as the turner becomes quite master of his tools, he will
find ivory much pleasanter to work than wood; it is not so liable to
split, it turns smoother, polishes with less trouble, and shows any
ornamental work much better than wood. But then it is very expensive,
and very difficult to obtain good and white. New ivory may be
bleached by exposing it in the sunshine, and wetting it constantly,
or it will crack; but till the ivory is cut up, you cannot tell
whether it will be good or not. Pieces may be bought cheaper that
have a hollow in the middle, they serve very well for pedestals of
vases, by screwing another bit into the hole, or for boxes, by gluing
in a piece of ebony to fit the hollow. Ivory is polished _before_
ornamenting, with putty powder, ground very fine, rubbed on with
a piece of linen dipped in water, dry it, and rub very hard with
a bit of felt, and the polish will be beautiful. But after it is
ornamented, polish only with a brush dipped in water and chalk, or
even in plain water.
For dying ivory, it is first necessary to cleanse it from the grease
which it always contains, more or less, and which would prevent its
receiving the stain or dye. For this purpose, mix half a pound of
nitre in an equal quantity of water, tie a string round the pieces of
ivory, and dip them in while the liquor is hot, then plunge them into
cold water.
TO DIE IVORY RED.
Take half a pound of pieces of scarlet cloth, put them into a clean
earthen pot; add one ounce of soft soap, after which pour in three
quarts of soft water. Boil all together for half an hour, stirring
it frequently, and squeeze the cloth several times, to extract the
colour. When this is done, have ready an earthen vessel, put into
it as much pulverized alum as will lie upon a sixpence, pour the
scarlet liquid over it, and extract all the colour from the cloth by
pressing it in a canvas bag. Steep the ivory in this liquor till it
becomes of the proper scarlet.
BLACK DYE.
Boil a quarter of a pound of logwood shavings in a quart of water, in
an earthen vessel, for half an hour. Steep the ivory in it.
On taking the ivory out of these boiling liquors, immerse it
instantly in cold water, to prevent its cracking.
ELLIPTIC TURNING.
This machine is frequently called, by those who do not understand the
ellipse, an oval chuck; but it is not oval, for an oval expresses an
object that is smaller at one end than at the other. Fig. 1, plate
3, is a front view of the machine. I K is the iron plate to which
all the parts (except the ring, hereafter described) are fastened.
A screw, similar to that on the nose of the mandrel, is riveted to
this plate, fig. W, and upon it whatever you wish to turn is fixed.
Fig. 2 exhibits a back view of this machine; at each of the four
corners there is a short square pillar, marked D. Within these are
two narrow ribs of steel, reaching the whole length of the plate I
K. Each of them, being bevelled, forms an angular groove, reaching
all its length. By means of these grooves the slider, F, moves up and
down.
[Illustration: _Plate 4._]
When the slider is in its place, two pieces of steel, M M, bear upon
the side pieces, to which, and to the plate, I K, they are firmly
attached by four screws, X X X X. The plate, F, being cast in the
same piece as the slide, cannot be thrown out of its place, but moves
in a longitudinal direction only, the nut, L, acting as a stop to
prevent its going too far. The space between the end pieces, M M, is
just equal to the diameter of the ring, O, Fig. 3, upon the outside
of which they revolve when the nut is screwed upon the mandrel. Two
arms, R R, are connected with it, and in each there is a groove
extending nearly their whole length. This machine is connected
with the lathe, and its motion obtained as follows:—E E, fig. 4,
represents a headstock, through which two holes are drilled, the
centres of which are precisely in a line with the centre of the
mandrel, M; the ring is fastened to the headstock by two screws,
I I, the shanks of which pass through the grooves and through the
holes in the headstock. When the ring is in this position, it will
be perceived that it can only move from side to side, and its centre
must always be in the same horizontal line with that of the mandrel.
Now screw upon the mandrel the nut, L, fig. 2. The plate, I K, if
set exactly opposite the mandrel, will revolve in a circle; but if
the centre of the ring be the least in the world on one side of the
mandrel, it will revolve in an ellipse. When, therefore, the work is
fastened to the screw, W, it is quite as easy to turn an ellipse as
on the ordinary lathe to turn a cylinder.
Of course, the slider must move with great steadiness and freedom,
to effect which, very great accuracy in the workmanship must be
observed. Figs. 5 and 6 are two different views of the machine,—5 is
the side, 6 the end view.
To turn a hollow sphere, the convex surface is first turned, and
perfectly smoothed and finished; it must then be bored with a
centrebit, to make an aperture sufficiently large to admit the tool,
fig. 7, plate 1, with which the interior must be worked away. As,
however, it would require a large aperture to enable you to hollow
out the whole sphere, it is preferable to make six openings with the
centrebit, each in a line with the centre; they must also be made
at equal distances from each other, and every hole must be at right
angles with all the rest, except one, which is exactly opposite to
it. Place the sphere in a chuck, with the middle of any two of the
holes in a line with the axis of the mandrel; turn out as much as
you can of the first hole, then bring the other holes forward and do
likewise; at last the excavations will be cut through.
To turn the Chinese balls, which are so much admired for their beauty
and curious workmanship, we are told to proceed as follows:—As they
are composed of spheres one within the other, the holes must be just
deep enough to leave the thickness between each little more than the
diameter of the smallest sphere. The work must be begun by forming
the innermost sphere, and afterwards it must be continued regularly
on to the larger, till at last the outer sphere is completed.
An immense, almost an endless, variety of figures may be worked in
the lathe by carefully regulating the tools. Beautiful flowers in
ivory, equal to the Chinese carving, are formed by the experienced
turner, with small wheels and other instruments: medallions, even,
are executed in the lathe, with machinery so constructed that the
tool follows on the wood the exact lines of the head that is being
copied.
Gold and silver ornaments, such as watches, snuff-boxes, and other
trinkets, are worked with what is called a rose engine; plates with
patterns indented upon them are fastened upon the mandrel: the screw
regulates the tool, which produces an exact counterpart of the
pattern.
Many of the copper cylinders used in printing calicoes afford curious
specimens of engraving in the lathe. It is impossible to imagine any
thing more beautiful than the effect produced, and a whole web of
linen is printed by them in a very few minutes. The methods employed
in this kind of turning by the various artists who practice it are
but little known; and, indeed, to look at the patterns produced, it
would be supposed that the graver must have been used to form them. A
general idea of the nature of the work is all we are enabled to give.
The pattern intended for the cylinder must be cut upon a small steel
wheel, which revolves upon an axis. This wheel is then to be held
against the copper cylinder, which, quickly revolving in the lathe,
carries it round, and receives from it the impression of its pattern.
The wheel operates like a punch, but the roughness it makes on the
edge of the work is easily polished down.
Having now finished the directions for concentric and elliptic
turning, we will, before beginning the ornamental parts of this
interesting art, beg to impress upon the minds of our readers that
they must never be discouraged by failure in their first attempts,
even though they may be subjected to many disappointments; for, as
the Bard of Avon expresses it:—
“Oft expectation fails, and most oft there
Where most it promises; and oft it hits
Where hope is coldest, and despair most sits.”
ECCENTRIC TURNING.
[Illustration: _Plate 5._]
This name includes all the various, beautiful, and intricate work for
which the powers of a lathe are so justly celebrated, and which, once
seen, must be admired by all who love the fine arts and examine the
powers of machinery. The eccentric cutter, the drill, the eccentric
chuck, and the universal, or vertical cutter, are all indispensable
for those who wish to perform ornamental turning, and with them the
most delicate and intricate patterns can be worked with a precision
and accuracy that are truly wonderful. A sliding, or parallel, rest
is absolutely necessary for turning patterns, as upon it, in some
degree, depends their exactness. Fig. 1, plate 5, is the drawing of
one. The foot, A, screws firmly to the bed of the lathe, like the
common rest, and the upper part fits into the socket, B, and, by
means of the nut, C, is turned in any direction you wish. D D is a
bed of steel, five or six inches long; through the groove down the
middle is a screw which passes from one end to the other, and, by
turning the squarehead, E, the tool slider, J, is pushed backwards
or forwards, while the rest itself remains stationary. The steel bed
is graduated. Between the bed and the screw, E, is a small brass
wheel, divided into numbers, G; this regulates the position of the
tool. The tool slider, J, fits into the bed, H, and slides in and
out; J is the part where the tool slips in, and it is kept firm by
a screw, K. The handle draws it to and from the work, and the nuts
_l_ _l_, regulate the depths of the cuts. The tools belonging to
this rest, 1, 2, 3, 4, 5, are of steel, about two inches long, and
are ground to different angles: there are various sizes of each.
When you intend to ornament a piece of wood or ivory, first turn
it quite round, and smooth it with the common tools; you must then
make the surface _perfectly flat_, and to accomplish this, adjust
the sliding rest at a proper distance, put in one of the round-ended
tools, No. 5, let it just _touch_ the wood by setting the screws,
_l_ _l_; put the lathe in motion, and gently approach the tool to
the work; if it cuts too deep, tighten the screws a little more; if
too little, push the screw forward. Keep the tool steadily up to the
work by pressing on the lever, S, which impels the tool to slide
forward, then, with the right hand, turn the head, E, by means of
a handle, P, which will thus enable the tool slide to run from one
end of the brass bed to the other, at the same time that the lathe is
turning rapidly round, and thus the surface of the wood is rendered
perfectly smooth, level, and polished. Sometimes, however, it will
require to be worked over in this manner three or four times before
it becomes quite flat; and frequently, even when it appears level,
there will still be a hollow in the middle, which will quite destroy
the accuracy of the patterns: to discover whether this is the case
or not, take the T square, see plate 1, fig. R; place it with its
edge against the wood: if you can see light between it and the work,
the surface cannot be even, and requires smoothing over again. The
next process is to cut very delicate circles all over the work, at
regular distances: this is done to take off the bright look of the
wood, that the patterns may appear to greater advantage. Put into the
tool slide a double angular tool, No. 4; adjust it so as to make a
distinct, but still delicate, cut into the wood. Make one cut in the
middle of the work; move the brass wheel, G, one number, or from 1 to
2; make a second cut; move to 3, then to 4, and so on: each circle
you will find enlarges gradually, till you arrive at the end of the
wood. Pattern 1, plate 6, is a specimen of this work; but remember,
it is merely a preparation for other patterns. In doing _side work_,
as the side of a box, or a knitting-case, unscrew the screw C, and
turn the brass bed of the rest round till in a line with it, then
proceed as directed for face work. The wood being ready, we will now
go on to give a description of the eccentric cutter, plate 5, fig.
2. Like the tool slider, it fits into the sliding rest, but now it
is no longer the work which moves round and the tool stationary,
but the wood remains firmly fixed while the tool rapidly revolves
and cuts the patterns. For this purpose, it is obviously necessary
that the fly wheel should turn the cutter, while the small wheel
remains immovable. Several methods are used to perform this: the one
given plate 4, fig. K, is the easiest. The frame here represented
should be of iron, firmly screwed to the bench of the lathe, and of
sufficient height to be about a foot above the head of the workman.
In front is a spindle, which works in two nuts, No. 1 1, exactly in
a line with the mandrel. Two wooden wheels, No. 2 2, are fastened
to this spindle; the one on the left hand remains stationary over
the fly wheel of the lathe, by which it is turned, the other slips
backwards and forwards, according to the work it is required to do.
Take off the usual catgut from the fly-wheel, and pass a long one
over it, and over the small wheel on the over-head frame, No. 2.
When the cutter, 2, plate 5, is fixed in the slide rest, draw the
other small wheel on the spindle, No. 2, forward, till just above the
rest, then pass a catgut over it, and round the small brass wheel,
B, of the cutter, and the whole will turn together. The brass wheel
of the lathe must then be fixed at one particular number. It is
usually divided into three hundred and sixty divisions, each marked
by a small hole in the brass wheel, as in fig. A, plate 4, and it is
by properly dividing the numbers on this plate that the accuracy of
the patterns depends; to keep the wheel steady, a small steel key,
_h_, plate 4, is slipped into the brass knob, O, plate 4, and the
other end, being pointed, enters into one of the small holes, say the
one marked 360; the work is then immovable until you remove the key
into another hole. The cutter itself is of brass, with a spindle,
C, which works in two brass collars. At one end is the wheel, B, by
which it is turned, at the other a steel frame, T D, which is marked
on the upper edge in small lines, E, to regulate the quantity of
eccentricity. The steel tool-box, F, holds the tool, which is kept
firm by a small screw underneath. By means of a screw through the
frame, D D, similar to that of the sliding rest, the tool is pushed
backwards and forwards, and cuts a large or a small circle. G is the
nut that moves it, and it also is divided into numbers. This cutter,
for many patterns, is quite as useful as the eccentric chuck, but,
in conjunction with the former, is invaluable, and the patterns
performed by them may be multiplied according to the taste and genius
of the turner. The two screws, H H, fix the depth of the cut; the
wheel of the sliding rest determines the necessary distance, that of
the cutter the eccentricity, while the brass wheel keeps the pattern
accurate. The tools, Nos. 1, 2, 3, 4, 5, plate 5, are of various
forms and sizes: care must be taken not to break them, and the cutter
must be constantly well oiled with olive oil; the holes, K K, are
made to receive it. In using this tool, make the wheel of the lathe
go very quick, but approach the tool very gently and slowly to the
work. The better to do this, the lever, S, is used; it enters into
one of the holes in the side of the cutter, and into a similar one in
the sliding rest, so that by a slight pressure the tool is impelled
gently forward. There are generally about two dozen tools shaped like
those in the plate, but of various sizes.