Part 6

Plate 13 contains several specimens of eccentric turning. The temple may be made either of wood or ivory, and be left open, as in the plate, or have a coloured card-board case made to fit inside it. The upper and lower parts of the pillars, six in number, are fluted with a round-ended drill, but the middle parts are worked with the eccentric chuck, and are curious specimens of its powers. They much resemble a spiral staircase, and though at first sight they may appear difficult, yet they are not so when properly explained. Begin by turning the wood or ivory perfectly cylindrical with the slide-rest tool. This done, screw your eccentric chuck _one turn_ downwards, and turn the screw of your rest _one turn_ forwards, moving 12 numbers on the eccentric chuck wheel for every step. As this requires great nicety, delicacy, and care, (the cuts being very deep,) you must no longer depend upon the lever to approach the tool (which is No. 1, of the slide-rest tools) to the work; instead of using it, screw one of the screws, L, at the end of the tool slider, to the deepest cut, and leave it so; then, as you push the tool against the wood, gently unscrew the other screw, L, till the first one prevents its cutting any deeper. For every step, move exactly the breadth of the tool. If the piece you are working is thin and long, it will be necessary to use the back puppet; in which case remember to draw it away from the wood at every change of movement; for, of course, when the eccentric chuck is altered, the centre of the work becomes altered also. Nos. 1 and 2 of plate 13 are different patterns for pillars, both worked _without_ the eccentric chuck. The depth of the cuts, it will immediately be seen, form the steps. The rings now demand our attention; the tool used for forming them is No. 6 of the slide-rest tools, plate 5; one side of the tool cuts the outer; the other, the inner part of the rings. Put the tool into a handle, where it must be held firm by a screw; the same handle will be very useful to hold the slide-rest tools for making mouldings and delicate ornaments. The end of the ring tool, No. 6, being very sharp, cuts a road for itself into the wood or ivory, then press it gently to the left, till you find one half of the ring is formed, which will be seen by its filling up the half circle of the tool; then remove the tool to the outside of the work, and press the other side against it till the ring falls off. It is a good way to turn a small cup and line it with velvet, or some soft article, into which to allow the rings to fall, as the delicate ones would be apt to split by striking against the steel bed of the lathe. To form the chain, cut the rings carefully through on one side with a sharp penknife, and slip them one through the other. The handles of the temple are large rings, the pins they hang upon are of wood. Flatten the knob either with a file or a small saw, and drill a hole through it to receive the ring; the pin is then glued into the moulding.

The ball at the top is turned quite round, and may be ornamented with the circular rest. The ball pendant from the chain is circular, except on one side, where a small pin is left, through which drill a hole and slip the ring through it. All the ornaments, pillars, and flutings may be made of separate small pieces of ivory, which, when worked, are easily fastened together by a strong cement made of isinglass melted in gin. The top of the temple may be worked with the universal cutter, or the drill, and the feet are turned quite round, and then ornamented with the eccentric cutter, as directed for the stopper of the bottle, B, plate 9. The needle-case, E, in plate 13, is also a specimen of curious turning; the whole thing should be of ivory, or else the twists of ivory, and the pillar in the middle of cocoa, or some dark wood. Turn the ivory perfectly cylindrical, and hollow it very carefully; this done, throw your eccentric chuck four times outwards, the screw of the sliding rest one turn downwards, and the eccentric chuck wheel four numbers for each plate. The other twists are each worked exactly the same, and they must have a small pin left at either end, which is glued into the moulding. When your centre pillar is hollowed, fit the twists to it.

Another method for working this pattern is with the aid of the drill, and by this means the twists are in the _same_ piece of ivory as the pillar. Having formed a smooth cylinder, hollowed it out, and made the screws, take your largest flat-ended drill, and drill fifteen holes round the pillar, or one at every eighth number of the eccentric chuck wheel. Your ivory must be very thick, to enable the tool to cut very deep. Having cut one row of holes, slowly and carefully, you must move the sliding rest forward two turns, then cut another hole every eighth number again; do a third circle the same, moving the chuck and slide the same every time. Now examine your work, and see whether the twists begin to appear. They should, as in the plate, be quite _separate_ from the ivory tube in the middle, being only joined at the top and bottom. For this no exact rule can be given, as it depends on the circumference of the work: if very large, the tool must cut very deep to detach it: but, after trying two or three times by these directions, it will be found quite easy. As the ivory twists are, of course, very delicate, and the least jar in working is apt to break, do not use the lever, but employ the screw guides, as directed for the spiral turning. _Line_ the ivory before beginning the twists, and leave about half an inch at each end, which you can ornament with the cutter: this gives strength to the work. For the same reason, it is advisable to cut one piece of your ivory longer than the other: on the shorter one make the outside screw, and below it about half an inch of ornament; on the other, make the inside screw, and work it with the cutter to correspond with the other part, quite beyond where the screw extends. When screwed together, it will not be perceived that the two pieces are not even; and as the part where the inner screw is worked is, of course, thin, you would have no thickness for the spiral pattern. When one end is finished, put a fine double angular tool into your cutter, and very carefully cut some circles at regular distances between the twists: this adds much to the curious effect of the patterns: to do it, work backwards, counting the same numbers on the chuck wheel and on the sliding rest as for the twists.

Patterns that are not cut deep can have the impression taken off on paper, either by slightly rubbing the wood over with printers’ ink, and laying upon it silver paper, which must be pressed down upon it; or by laying the paper on the wood, and rubbing it well with a piece of lead melted into the shape of a pencil. Patterns on ivory also look very well by rubbing a little printers’ ink well over them till the lines are full of it, then wipe off the superfluous ink from the surface, and the design will be black on a white ground.

An immense variety of most beautiful and intricate patterns are worked with the eccentric cutter, in conjunction with the eccentric chuck; indeed, many of those formerly supposed to be only done with the double eccentric chuck, invented by Mr. Ibbetson, can be worked by these two when used together, but they require much patience, and knowledge of the powers of the eccentric chuck, to enable the learner to use them properly. When the eccentric cutter is used, always set the tool exactly in the _centre_ of the work, at its lowest degree, before you begin any pattern, or you will never be quite sure that your work is done straight; when once you have settled the centre, the patterns will diverge regularly and evenly from it. In the patterns we are going to describe, the slide rest fixes the position of the tool; the chuck must be screwed down to the proper situation to meet it, and the cutter tool must then be screwed out to cut the circle required.

PATTERN 1, PLATE 14.

This pattern is formed of four groups of circles, containing seven in each. Your wood being perfectly smoothed and _lined_, set the cutter tool (a double angular one) at its lowest degree, exactly in the centre of the work, so that if moved it would only cut a dot. Unscrew it eight or ten turns to make a large circle, then by impelling the cutter box forwards with the slide-rest screw, fix it so that the tool cuts the circle a little _over_ the centre: arrange your screw guides: having cut one circle, count 30 on the eccentric chuck wheel, and the same for the other two. It will be observed that these four groups go in straight lines, each towards the edge of the work; to perform this, in the six following rows of circles, move the slide rest forwards half a turn, and the small wheel of the eccentric chuck half a turn upwards for each row of four circles, counting 30, as before, till the twenty-eight are all done.

PATTERN 2.

Arrange the circle a little smaller than for pattern 1, and on a level with the centre point of the work. Set the chuck wheel at 120, cut a circle; then one at 15, 30, 45, 60, 75, 90, 105, when you will find the eight _outer_ circles of the pattern are formed. Then move the slide-rest screw forwards four numbers, and to No. 1 on the eccentric chuck wheel; then to Nos. 14-31, 44-61, 74-91, 104. By following the same rule in the other circles you will find the pattern is not difficult, though at first it may appear very intricate. As all depends upon properly counting the numbers on the eccentric chuck wheel, to make the calculation more easy, I give the proper numbers for the sixteen circles composing one cluster, and you will then see that the others can readily-be done the same, always remembering to move the slide-rest screw forwards four numbers for every row; 1, 15-2, 14-3, 13-4, 12-5, 11-6, 10-7, 9-8; the latter single number forms the centre or outer circle near the edge.

PATTERN 3.

This pattern requires great attention and care to work it properly. Having arranged the cutter tool, screw it out four turns to make the circle the proper size, then move the cutter to the edge of the work, cut a circle at Nos. 120, 40, and 80, on the eccentric chuck wheel, then set the wheel at 20, and leave it fixed. Your next operation must be to screw down the eccentric chuck, and alter the position of the tool on the slide-rest, till, by laying your hand on the fly-wheel and moving it gently, the tool of the cutter appears to describe a half circle _across_ the wood, in the same way as for the arc patterns. Having arranged the first arc, move 40, as before, and see whether the second will exactly meet it, then the third; they should each diverge from the centre of the first circles which were cut round the edge; if they do not exactly fit, move the chuck up and down, and the slide-rest screw backwards or forwards, till you find the exact position; as, however, the arc is difficult to settle, the line being of course an imaginary one, as the tool must not touch the wood, it is a good way to cut a piece of pencil to fit like the tool into a box, and with it mark the arcs; they will easily rub out, and thus you will be able to be more certain of your proper distance and position. The next thing is, to see on the fly-wheel of the lathe how many numbers are required to form the arc; thus, if it begins, as the one I have worked did, at 360 of the brass wheel, and ended at 85, stop the wheel at the former number, cut a circle, then one at every fifth number on the same wheel, till you arrive at 85; then move forty numbers on the eccentric chuck wheel, and do the other arc the same; then the third one.

PATTERN 4.

The arc pattern is first worked: arrange it as directed for pattern 3, and mark the outline with a pencil: in this, the arc began at 280 of the fly-wheel, and ended at 168, making in all 116 numbers; to divide 58 for each half of the arc, divide them thus—4, 5, 6, 7, 8, 9, 10, 3, 4; then count back 4, 3, 10, 9, 8, 7, 6, 5, 4. You will see that the numbers increase one every time or for every circle, which also is enlarged one notch for each. Having made the three arcs fit by marking their position with the pencil in the cutter box, cut a very small circle at 280, enlarge one notch, count 5, cut another, enlarge a notch, count 6, and so on till you have counted, in all, 49 numbers; do not enlarge the circle, but cut one, counting three numbers, then 4, which will be the middle, then 4 again, then 3, then 10; after 10, decrease the circle one notch for every cut, and count backwards, 9, 8, 7, 6, 5, 4. The other three arcs are done the same, by counting 40 for each on the eccentric chuck wheel; for each of the crowns cut five circles just above the arc, by counting one number for each circle on the eccentric chuck wheel, then lower the chuck one number, and cut the same circles again through the others; lower it half a turn more, and cut two circles; then half a turn again, and cut one circle above and between the last two.

PATTERN 5.

Set the cutter to the middle, enlarge the circle four turns; then turn the slide-rest screw two numbers to the right, cut one circle, and for each of the other eleven, screw the chuck down one turn, then return to the middle and cut eleven the other way. When 23 are finished, screw the slide rest to the left four numbers, and cut 23 more exactly in the same manner. To work the side patterns begin by that on the right, set the cutter to the middle of the work, unscrew it two turns, move the cutter slide twelve turns to the right on the slide-rest, cut the middle circle, enlarge one number of the cutter, lower the eccentric chuck one turn, and, to keep the _outside_ of the circles in a straight line, move the screw of the slide-rest inwards half a number: proceed the same till the nine circles are cut, then return to the middle circle by counting back nine turns of the eccentric chuck, nine numbers of the cutter, and four and a half numbers on the slide-rest; proceed exactly in the same way to cut the other eight circles, only _raising_ instead of _lowering_ the eccentric chuck one turn for each circle. The opposite pattern is worked the same, only taking care to turn the slide-rest screw outwards the half turn for every circle, or the straight pattern will come contrary.

In all these straight patterns take great care that the fly-wheel is stopped in such a manner that the eccentric chuck stands perfectly upright: to do this, hold the T square against one side, and make a mark on the brass wheel for the stop to enter. When you are quite sure that the chuck inclines neither to the right nor the left, drill a small hole in the wheel sufficiently deep for the stop to hold it quite firm. You will then find your patterns will always come straight.

PATTERN 6.

Set the cutter to the centre, enlarge the circle six turns, cut one, diminish one number on the cutter for each of the other eight circles, and move the eccentric chuck downwards one turn for each. Count back to the middle circle, and work the other eight the same. The side patterns are done much like those in pattern 5, only the large circle is in the middle, and the straight lines incline inwards.

PATTERN 7.

Set the cutter to the middle of the circle, enlarge it two turns and a half, cut a circle in the middle, turn the chuck down two turns, so as to cut another a little into the former ones; continue the same till the seven are done; return to the middle circle, and cut the other six in the same line, by screwing the eccentric chuck upwards instead of downwards. When the thirteen are completed, lower the chuck one turn, and screw the slide rest outwards (if doing the lines to the right) two turns, cut a circle, then move the eccentric chuck downwards as before, till the second line of circles is cut, each line diminishing one turn of the eccentric chuck at the top and bottom.

PATTERN 8.

Set the cutter to the middle, enlarge it two turns, turn the slide rest outwards twelve turns, cut a circle near the edge; count 20 on the eccentric chuck wheel, cut another, then 5 more, each distant twenty numbers from each other. To make the circles join in straight lines, screw the eccentric chuck downwards two turns for every one; when the outside pattern is done, return to the middle circle, and cut the other lines the same.

PATTERN 9.

Square patterns require great care in working them. First saw the wood perfectly square; then, when on the lathe, take the T square; hold the flat edge firm on the bed of the lathe, and the handle against one side of the wood, till both are even, then fix the wheel of the eccentric chuck to that number. Having with the cutter worked one row of patterns, move the chuck 30 numbers, which, if the wood is quite square, will enable you to do the second row; then 30 more for the third side, and 30 for the last.

We are told, that French and Italian turners often line boxes with the peel of the Bergamot orange; they cut a circle through the peel, and carefully strip it off in two quarters, turning the inside out, and drying them; the scent is very powerful; of course they can only line globular boxes the size of themselves.

TO LINE WOODEN BOXES WITH TORTOISE-SHELL.

As many of my readers may wish to line their snuff-boxes with tortoise-shell, I think it needful to give some instructions in the best method of doing it. Cut the shell into very thin leaves with a sharp fine saw, then divide these into the size you wish for the inside of the snuff-box, leaving a very little extra for the joint. Take a new rough file, and scrape away a little of the two _ends_ of the narrow strip of shell, so that they can lie one upon another, and fit so closely that the aperture is hardly perceptible. Plunge the tortoise-shell into warm water for a few minutes, and it will become quite soft. Have ready on the lathe a piece of wood a little _less_ in circumference than the inside of the box, and perfectly round and smooth. While the shell is soft, place the joints together, wrap a wet piece of linen tightly over them to hold them fast, and press them firmly together with the finger and thumb. Then heat a pair of tongs to a proper heat, (which is known by trying them on writing paper; if they brown it, they are too hot; if they only turn it yellow, they are right,) and with them compress the joint of the tortoise-shell. The water, the heat, and the pressure united, will make the two parts join firmly. When finished thus far, file away any roughness that may remain, and steep the shell into hot water till quite soft, then slip it upon the piece of wood before mentioned, and see if it fits it perfectly; if not, try with pressure to give it the requisite shape; and if this does not succeed, take the wood out of the lathe, leaving the tortoise-shell upon it, and hold them over a brazier, turning them frequently and quickly between the hands, that the heat may equally penetrate all the parts; then strike the side that bulged out with a mallet, and with a little care it will soon assume the required form. You may finish it on the lathe, observing only to place it so that the tool does not catch the lap of the joint, which might cause it to open; and when you take it off, plunge it in cold water to make it retain its form.

TO FINISH THE SNUFF-BOX.

Make your box and lid of hard, well-seasoned wood; hollow them out, and polish the insides, only omitting to cut the lip upon which the lid fits, and which will be formed by the tortoise-shell. As you hollow out the box and lid, keep fitting in the shell, that you may not make them too large; when it slips in rather tight, take a point tool and cut some circles on the inside of each; (this is done to enable the glue to hold firmly.) Now, take the tortoise-shell and file that part that is to be cemented to the box, so as to make it rough. Take a pair of compasses, in one end of which is a sharp knife, set them to the exact size of the inside of the bottom and lid, then place them on a piece of tortoise-shell, and cut out the two round pieces. Melt some glue till rather liquid, thicken it with vermilion, lay a coat on the inside of the top and bottom of the box, and press in the two circles of tortoise-shell; in the same manner glue in the sides, leaving the lip (upon which the lid is to fit) standing up above the bottom part of the box. Leaving the glue to harden for a day, then replace the work on the lathe, turn the inside quite even, and polish it with pounce powder and oil, then with tripoli powder and water. Should the lid, when finished, become too small for the box, dip it for a minute in boiling water, fit it on to a piece of wood the exact size, and leave it there to harden.

HORN TO IMITATE TORTOISE-SHELL.

Dissolve three ounces of potash in a pint of boiling water. Let it boil for a quarter of an hour, then pour it into a basin capable of holding about as much again, and in which you have put half a pound of quick lime, stir it well, and when the latter is _slacked_, add three ounces of red lead and one ounce of vermilion.

When the whole is of the consistency of thick soup, dip a thin pointed stick into it, and lay the drops it will take up upon a piece of horn in those parts required to be coloured, leaving those that are to be transparent. When quite dry, clean the whole with a wet sponge, and you will find it will greatly resemble tortoise-shell.

MASTIC USED IN TURNING IVORY VERY THIN.

To turn ivory as thin as writing paper, so as to render it quite transparent, is very difficult to accomplish, but is much admired when done, and shows the skill of the artist. To enable the ivory to bear the action of the tool without splitting, the following mastic has been found very useful, both for strengthening it and for giving a deep colouring, by which means the thinness is more perceptible. Some turners wet the ivory for the latter purpose, but as when wet it is quite transparent, and thickens again when dry, the mastic will be found much preferable.

Take some lamp or ivory black in powder, and strain it through a fine sieve, so as only to retain the finest parts. Steep these in water to free them from any impurities. After lying in it a few minutes, pour off the water, and make some glue very hot, mix it with the lamp black till of the consistency of oil paint. This mastic must be kept warm near the fire, and when you have sufficiently hollowed out the vase, or whatever you wish to turn, very thin, shape the outside a little: then dip a large camel’s-hair brush in the warm varnish and lay a thick coat all over the inside; let this dry, put on another, and repeat the process till sufficient strength is obtained. You may now, without fear or danger, work your ivory as thin as possible, and ornament it with the cutters and drill. Without this mastic it would not, when transparent, bear the force of these tools.

When the work is all finished and carefully polished, take it off the lathe, and put it in a basin filled with warm water. After a few minutes’ immersion, take it out, and plunge it in clean water, shaking it gently. This will make the mastic dissolve and leave the ivory. Renew the warm water frequently, as leaving it in the blackened liquid might injure the colour of the work.

BEAUTIFUL VARNISH FOR WOOD, TO BE USED WHILE THE WORK IS ON THE LATHE.