The spindle of the large iron wheel is made round at D, Fig. 3, where it works in the floor of the bench. That hole should be lined with soft leather, fitting the spindle like a glove, and kept well oiled. An iron plate (A) keeps the spindle in position. The spindle is, of course, square where the crank grips it at B, and a nut (C) screwed tight keeps the crank in position.

The legs of the bench are let into sleepers (X Y, Fig. 1), screwed firmly to the floor of the room, and clamps at C and elsewhere screwed to the wall of the room may give additional rigidity. The bench must stand true and fast, so that there may be no oscillation during work. It should be placed in front of a window, as plenty of light is desirable.

The following requisites must now be procured. Seven pounds of emery ‘46-hole’; some fine sifted silver sand; some rottenstone in lumps—the hardest is best; some putty powder. Then you will want a housemaid’s blacklead brush, a nail brush with handle, a brush used for cleaning silver plate. These should be old and nearly worn-out. A large earthenware vessel for water to stand on a stool or table at the right side of the bench within easy reach, and three jampots for water. You see that the furniture is of the humblest description.

All being now ready, we may hope to commence operations in polishing a pebble.

III.—HOW TO POLISH A PEBBLE.

There are three distinct processes in polishing a pebble—grinding, smoothing, and facing. Let us take this pebble, a choanite, of a kind which I found at Sandown, Isle of Wight, and which I polished in the first of the only four lessons I ever had. It is a beautiful little rounded choanite, rather flattened on the upper and under surfaces. It is too small to be held comfortably between the thumb and two first fingers. We must therefore fix it upon a cement-stick. So we must manufacture some cement as follows. Here is the recipe:—

1 lb. of pitch, ¹⁄₂ lb. of resin, ¹⁄₄ lb. of shellac, 1 oz. of beeswax, must be broken up and put into a good-sized saucepan. Begin boiling the mixture upon a fire, and as it boils add gradually 1¹⁄₂ lb. of Spanish brown, stirring all the while until all the ingredients are thoroughly mixed. Pour the contents of the saucepan upon the stone flags of the kitchen floor, or any pavement, in portions a foot in diameter. When cold remove the cement by a kitchen knife inserted underneath. Make some pieces of wood 4 in. long according to the shape in Fig. 4, and melt on them a portion of cement as shown at B. A nail driven into the wood at A and C will strengthen the cement. Fashion the cement into shape with the fingers well wetted. Warm the stone, and again melt the cement over a candle. Apply it to the stone, and work it on with the fingers. Be sure you have the stone firmly fixed. To test it, plunge the stone and stick into water, and when it is cool see if you can pull the stone off. The diagrams in Fig. 5 show the phases of cementing a stone. If the stone is insecure, pull it off, and warm and melt up again. Practice makes perfect.

The first stage is that of GRINDING. Set up the lead lap as shown in the drawing of the bench (Fig. 1). Put a heap of emery in the left corner of the right compartment (J). Put a jam-pot of water at Z. Take the old blacklead brush, dip it in water, mix up some emery with it into a paste; wet the lap; brush it well over with emery. Take your cemented stone in the right hand, between the thumb and two first fingers; turn the handle N slowly from right to left, and as the lap revolves press the stone upon it. Grind away, understanding that you want to grind down all irregularities on the surface of the pebble. Try and throw the weight of the body through the right arm and wrist into the pebble. Emery is harder than flint. The pressure forces the emery into the lead lap, and so its surface is converted into a powerful rasp. Pause at intervals to brush fresh emery over the wheel. ‘Don’t spare your emery!’ was an exhortation I often heard when receiving my lesson. Do not attempt to do the whole surface of the pebble at once. Begin at a corner and finish it fairly, and so pass on to adjacent parts. Work towards the centre of the lap when grinding round surfaces, and keep the flat margin of the lap for flat stones.

Ah, your right hand begins to ache as it never ached before! You must not mind. Rest a while, and then at it again! You are bringing muscles into play which are unaccustomed to the work, and the strain will be felt until the muscles are strengthened by the exercise. Keep washing the pebble at intervals with the nail brush in the earthen vessel to see how the work progresses.

The surface of the pebble where you have been working now looks smooth, and the feelers of the choanite are vividly shown. Finish in the same manner the whole surface. Feel that you bring the weight of the arm—and even of the body—to play through the wrist of the right hand upon your stone. Do not forget the emery and washing, and see that you keep the surface of the stone true and free from ‘ridges’ and ‘shoulders.’

When you think the surface is sufficiently ground, then continue working on the lead without putting on any more emery. Continue patiently so grinding until the lap works perfectly free from grit, and the emery on it has been reduced to soft black paste. This will make the surface of your pebble much smoother. The nearer you reach perfection in this first stage the easier will be the afterwork. If you continue long enough the stone will look half polished when dry before you have finished. Dry the stone periodically to estimate progress, remembering that a pebble always looks polished when wet.

We may suppose now that you have completed the first process, so we pass on to the second.

Smoothing.—Lift off the strap by raising the part nearest to you off the wheel, and let the strap lie loose upon it. The strap consequently falls off the reel. Unscrew Q. Raise the arm K L, which remains raised by its own weight. Lift the lead lap carefully out and put it aside. Set up the beech wood lap instead. Use another jam-pot of water at Z, and see that no emery-grit gets upon the wood lap. Dip your right hand in water and thoroughly wet the surface of the lap while it slowly revolves. Then dip the wet fingers in sifted silver-sand and rub them over the wood, and proceed as you did in the first process of grinding.

Our aim now is to smooth the surface of the stone, to carry to higher perfection the work of the emery. Do not go too fast, and keep the stone and lap well wetted, otherwise the heat caused by friction will crack the surface of the stone. Many a beautiful stone has been spoilt in this way. Do not use much sand. Wash and examine the pebble as you go on. See how beautiful it is getting to look! How wonderfully the texture and organism have been brought out by the smoothing! Make the work as perfect as you can upon the wood, and continue working your pebble without putting on any sand, until the wood seems free from grit. In the last stage of this smoothing process we work the stone almost entirely on moist wood, as the sand has been reduced to powder. Wipe the stone dry, and if you are satisfied that you cannot do anything more for it on the wood, we may pass on to the third process of facing the pebble.

Facing.—As before, remove the wood lap. And now we must proceed with extreme caution. We are going to set up the pewter lap. Bear in mind that ONE GRAIN OF SAND OR EMERY UPON THE PEWTER WILL RUIN YOUR WORK! The floor of the bench is covered with débris of sand and emery; there is a heap of emery in the corner. How can you possibly prevent catastrophe? Care and practice will bring success. Remember the caution, and you will do your best to keep clear of disaster. First of all sweep up the emery into a heap at J, keeping it well away from the vicinity of the lap. Thoroughly wipe the handle N, the clamp I, and the arm K L—everything that could bring a speck of grit upon the pewter. Shut the window, that no wandering breeze may work mischief. Wash your hands in a bowl of clean water, and put the bowl in place of the earthen vessel. Jam-pot of clean water at Z. Now set up the pewter lap. The first thing is to ‘notch’ the surface of the lap, that it may hold the rottenstone. This is done by holding a table-knife lightly by the handle in the right hand, and letting the edge of the knife play upon the surface of the lap as you slowly turn the handle N from right to left, and then from left to right. The result of this is to set up a ‘bibbering’ movement in the knife—such as you may notice in the bow when a nervous young lady is performing upon the violin. The surface of the pewter will soon be decorated, as in Fig. 6, with markings not unlike the pattern on the case of a watch. When this is done wash the surface of the lap by dipping the fingers of the right hand in clean water. Take a lump of rottenstone, thoroughly washed and free from grit, and press it on the pewter while slowly revolving. The rottenstone is conveyed as a brown paste to the surface of the pewter.

Now scrub the pebble, cement and stick with the plate-brush in the bowl of water, until you feel certain that no speck of grit lurks in any crevice, and begin working the pebble on the pewter lap as in the other stages, putting pressure through the wrist of the right hand, and letting the weight of the arm play, so that a sort of rhythmical movement is imparted to the pressure difficult to describe, but soon understood when you see a lapidary at work.

In polishing a round stone you must be careful to avoid producing ‘ridges’ by dwelling too long on one spot. Keep on turning the stone slightly. Common sense will explain my meaning. And in this last stage BE SURE YOU NEVER WIPE YOUR HANDS OR YOUR STONE WITH THE CLOTH USED FOR THE SAND OR EMERY STAGE. Use a clean cloth. It took me two years to find out the force of this simple advice. I could not imagine how it was that just at the last moment, when I was putting the finishing touches to a pebble, some faint but hideous scratches would suddenly appear on its surface, ruining the beauty of the work. How many times have I despaired of success! How often have I written to lapidaries imploring advice, and feeling that there was some ‘wrinkle’ which had purposely been kept from my knowledge! But perseverance was at last rewarded.

There is no ‘dodge’ about it; the whole operation is one of patient labour and determination. After a little working on the pewter lap at one portion of your stone, wash and wipe it. That portion ought to be so perfectly polished that when held slantwise towards the window it reflects the landscape like a looking-glass; and if your work has been true this result will make your heart leap with delight. Continue working until the whole surface of the stone is finished. If at the end portions of it looked blurred, it may be that the texture of the stone is incapable of a high polish in such places; it may more likely be that you have not been particular enough in the first and second stages. Nevertheless the result ought to be encouraging. Your stone ought to be so far polished that you will be proud to show it to your friends, and say, ‘I found and I polished this stone!’

Probably, if you have carefully followed out my instructions, the result will be very creditable for a first attempt. And this is all you have a right to expect.

Some lapidaries, after smoothing their stones on the sand lap employ an elm lap with powdered pumice-stone, and dispense with the pewter lap altogether, facing the stone on the felt lap with putty powder. This process is advantageous in polishing stones all over. But on carefully comparing the systems I am convinced that there is nothing like the pewter and rottenstone for general purposes; though the felt is advisable for round stones when they are to be polished over the whole surface. As you proceed you will be able to try experiments at your discretion.

To polish flat surfaces of pebbles we work exactly as we have described, the only difference being that you work the stone flat on the margin of the laps. If you thoroughly understand the principle you will find the flat surfaces easier to manage than the round.

Mussel and other sea-shells, snail-shells, etc., may be polished in the same way—only that being soft they will not require the emery lap. Work them on the sand lap and cloth lap, and a little experience will soon make you proficient in the art.

IV.—HOW TO CUT A PEBBLE.

We have reserved the process of CUTTING a pebble till the last, because it is advisable to understand the polishing process first. Many pebbles make most attractive specimens without being cut, but no pebble looks well after it is cut unless it be also polished. Therefore the polishing is the first essential, and I hope you thoroughly comprehend its principles and are enthusiastic about the whole subject.

To cut a pebble, with a view to polishing its inner surface, we want a spindle and reel as before, fitted with a disc of the thinnest soft iron. These discs are of particular make, and must be procured from a practised maker. You should get six of them, ten inches in diameter, from Mr. Oxley, 83, Caledonian Road, Islington, N. The shoulder for the disc to rest on should be about five inches from the upper point of the spindle, and the nut must be screwed home very tight to keep the disc in position. The disc is ‘panned,’ i.e., beaten into a saucer-shape so shallow as to be hardly perceptible to the eye. This precaution is necessary to ensure the edge of the disc being true, for otherwise it would be impossible to make such thin iron free from undulations in the edge.

The discs are by no means cut true when sent down, and as they must be brought to absolute perfection of truth before they can be used, the first thing will be to turn the edge true.

Procure three small triangular files, sold at fourpence each. Break an inch off the end of them, and grind them with emery on the lead lap into a pyramidal point (Fig. 7), with edges as keen as a razor and point sharp as a needle’s. Set up the ‘slitter’ (the disc and its spindle) in position, taking care that it stands truly perpendicular. Then arrange a wooden rest underneath the edge of the disc nearest to you, as shown in Fig. 7. The support must be securely fixed, and of the exact height to enable the disc to revolve upon it. Wet the edge of the disc, and turn the handle N with the left hand. Take a file and fix its point into the wooden rest, so that a keen edge may catch the edge of the revolving disc. This will take off a shaving of iron wherever it bites, and by degrees the edge of the disc will be turned true, and continuous shavings will curl off it. There is nothing difficult about this. It requires a neat hand, and you may want to use three files before finishing; but when you understand that you require the edge of the disc to be perfectly true you will soon attain the result; and by lightly applying the file to the upper and under surface of the edge of the disc you will remove any roughness caused by the turning, and the disc will be ready for use.

Remove the wooden support. Put a common plate under the slitter to catch the paraffin, which will shortly require notice.

The disc has now to be CHARGED WITH DIAMOND. This sounds somewhat alarming, but take courage. Diamond ‘bort’ consists of genuine diamonds not sufficiently good to be used for gems. It may be bought of any of the ordinary merchants at a cost of about six shillings the carat. That amount would be enough to cut about twelve or fourteen pebbles an inch and a half in diameter. This is the only serious expense when once the bench has been set up and furnished. And after all it is not very formidable. Take a fragment of bort, and crush it upon a piece of hard steel by means of a steel rod one inch in diameter and six inches in length. Put the bort on the steel plate; smear a little butter over the bort to prevent the broken pieces flying away. Hold the steel rod upon it, and give it a smart blow with a hammer. This crushes the diamond. Then pound it into the smallest possible powder, using the steel rod as a pestle.

Now pour some paraffin into a saucer (J, Fig. 8), and with a feather smear paraffin over the edge of the disc revolving slowly. Take some of the powdered diamond on the forefinger of the right hand, and very carefully transfer it to the edge of the disc. The entire edge must in this way be anointed with crushed diamond-dust. Then a smooth pebble is taken in the right hand (the hand resting comfortably on a support G), and pressed against the edge of the disc revolving. Let us understand exactly the object and action of this. The diamond-powder is the hardest known substance in Nature; the disc is of soft iron; the flint pebble is very hard. By the process just described we press the diamond-powder into the substance of the disc, so that the edge becomes armed with grains of adamant; the edge becomes a mighty file, or an irresistible saw. The principle is so simple. When you have driven sufficient diamond-powder into the edge of the disc, you have invested the iron with an armature which can cut through every hard substance that exists in Nature except the diamond itself. The hardest flint, emery, iron, glass, metals, etc., must all bow beneath its mighty power. I should like to shake hands with the man who devised this simple and clever method. Before its invention agates kept their treasures locked in close caskets. The diamond-toothed ‘slitter’ has supplied the key for unlocking their secret beauty.

Well, now, the disc is CHARGED, and if you wish to proceed like most of the lapidaries do, you will take the pebble you wish to cut between the forefinger and the thumb of the right hand, letting it rest on the second and third fingers. You will place the support in position, that the hand may rest comfortably upon it when holding the pebble against the disc; and you will begin turning with the left hand. You will soon see that the disc has begun to cleave its path. A distinct cut is visible. You must keep feeding the edge with paraffin by means of the feather; and as, unfortunately, you have not got a third hand, you must hold the feather between your teeth, or else get a friend to do the turning. It ought to take about half an hour to cut an inch through a pebble two inches in diameter. The disc will have to be re-charged with diamond occasionally, which may be done by using the slit of the pebble you are cutting as a ‘charger.’

Such is the method of cutting in vogue among most lapidaries. It answers very well for professionals, but it certainly presents more than one objection to amateurs. I found the objections so weighty that it required no small determination to persevere. First of all, it is very difficult to hold the stone true, so that the cut shall proceed in the same straight line; then the paraffin and detritus of the cutting cause such a disagreeable ‘mess,’ in which the right hand has to take up permanent quarters, and the nuisance of feeding the paraffin by holding the feather in the mouth is very great. Finding these objections a grave impediment to success, I bethought me of a device I once saw used by a lapidary, and improved upon it in design, and got a tool made by Mr. Moore, of Clerkenwell, which has proved the greatest comfort and most complete success, entirely obviating all the disagreeables alluded to above. The diagram (Fig. 8) ought to make it clear to you.

A B is a circular steel rod, with shoulder at B, and screwed underneath, rising ten inches above floor of bench. It has an arm (C D) moving easily round, which can be set at any height by screw and nut (E). At D is a hole large enough to admit the cement-stick with pebble attached. This is held securely by a screw at D. A string (F) is slipped over the cement-stick just above the pebble, with a weight attached to the other end. The string passes over a pulley (G) in the opposite side of the bench. It is obvious that the weighted string will always keep the pebble with even pressure against the disc. The result is that all difficulty in holding the pebble is removed. The pressure is constant, and the cut is made perfectly true. The right hand is now free to manipulate the feather for lubricating the disc, and you can work without getting a drop of oil upon your fingers. You turn the handle as briskly as you like. The large wheel multiplies the reel ten times—i.e., one revolution of the handle produces ten revolutions of the disc. I often attain a speed of fifteen hundred revolutions of the disc in a minute when cutting a pebble! Keep all points of friction well oiled, and everything will go merrily as a marriage bell. H shows the plate for catching the drops of paraffin and detritus from the stone; J shows the saucer of paraffin. The length of the arm (C D) is ten inches. When you want to recharge the disc with diamond, lift the weight at end of string, shift the arm and the stone to the right, feed the edge of the disc with diamond, and drive it in with a smooth stone as before described.

When your stone is cut through wash the halves, and remove the cement by heating over a candle. The same cement will do for many stones.

You must be careful not to bend the slitter or spoil its edge. Never put it away leaning on the disc. Keep it when not in use suspended by two strings, and wipe off the oil carefully when you put it away.

We have now gone through the various processes of GRINDING, SMOOTHING, FACING, and CUTTING pebbles. You have a clear knowledge of ‘how it is done.’ It remains for you to decide whether or not you are to become a practical lapidary. Remember that it is one thing to know how to work and another thing to put that knowledge into practice. If you resolve to take up the subject you should certainly make friends with some working lapidary, and get him to let you watch him at work, and if possible take a few lessons from him.

A POSTSCRIPT.

Since the foregoing chapter was prepared, W. B. has written to us from Ipswich: ‘I have been very interested in your article on stone polishing. I found, however, that with two hands free you could work the stone much better; so I bought a treadle and wheel (1 ft. 6 in. through) together, then for the grindery dovetailed two boards into one another, and having centred the upright ones, put a hardened coach-screw in, and turned an elm spindle 2 in. thick, and at one end turned a series of pulleys. Then at each end I drilled holes and screwed coach-screws in, after having centred their square heads and drilled a small dent for the other screws to work on. Next I got some wood “bobbins,” turned 5 in. through by 1¹⁄₂ in. thick at hole on spindle, tapering to ³⁄₄ in. The pulleys, of course, were for the driving speed, so that by putting the strap on the small one I could drive fast, and the large one slow.

‘Above is a rough drawing of the lathe part.

‘The best of this is you can screw the “lathe” to the table, and place the driving-wheel where you like, provided you lengthen or shorten the strap. I might add that the cost of the whole thing is under ten shillings.’

CHAPTER XXXI.—GRAPHS AND GRAPH-MAKING.
By Theodore Wood.

Although for the last year or two its popularity has been somewhat on the wane, there can be no doubt that the copying machine, known by the various titles of chromograph, hektograph, multigraph, centograph, and others of similar nature, is a most useful invention, and one which saves an immense amount of labour to all those who wish to draw out a number of copies of diagrams, plans, circulars, letters, music, etc., without calling in the assistance of the printer. Drawings, too, may be traced by those who have no original artistic powers, programmes may be made out for entertainments, and in a hundred other ways the machine will prove a most profitable investment. Its chief disadvantage lies in its expense, but as the entire machine can easily be made at home for a very small cost, this drawback is more apparent than real.

The process of graph-making is a very simple one, and cannot fail if the directions which I am about now to give are implicitly followed.

The apparatus required is of a very limited character. First you will want an old tin biscuit-box, sound as to the corners, and of moderate depth. A saucepan would answer better still, but as you would probably never get it clean again, I do not recommend its use. Then you will require a short stick or rod with which to stir the composition, a spirit-lamp (or a gas-jet will do nearly as well), and a stout carpet-needle fastened into the end of a wooden handle. Finally, you must have a shallow tray to hold the composition, and also the ingredients themselves.

The tray must be of metal, and nothing will be better for this purpose than the lid of your biscuit-box, unless you wish to make a graph of phenomenal proportions. In that case, of course, you must get an ironmonger to make you a tray of the required dimensions, and be prepared to add an extra shilling or so to the necessary outlay. For all ordinary purposes, however, you cannot improve upon the box-lid.

Now as to the ingredients, which, for a graph of medium size, will be as follows:—Glycerine (common), eighteen ounces; water, twelve ounces; sulphate of barium, six ounces; powdered loaf-sugar, three ounces; Nelson’s gelatine, three ounces. The first and the third of these you had better get at a manufacturing chemist’s; ordinary druggists are apt to charge rather highly for the former, and do not keep the latter in stock. Each ought to cost you one penny per ounce. Nelson’s gelatine you can procure from almost any respectable grocer at fourpence-halfpenny per one-ounce packet. The total cost, therefore, of the compound should not exceed three shillings and twopence.

Everything being in readiness, place the ingredients in your biscuit-box, taking care that the proportions are measured correctly, and place them on one side for four-and-twenty hours—this in order to allow them to macerate. Next day you will find that the gelatine has swollen to a wonderful degree, and has absorbed most of the water. Still, however, the mixture will be very far from perfect, and in order to complete it you must have recourse to heat. The best thing that you can do is to place the box upon the kitchen stove, and there leave it for two or three hours until the gelatine has melted. Take care, however, that the heat is not too great, or your composition will probably be spoiled.

Every half-hour or so stir the contents of the box with your stick, in order that they may thoroughly amalgamate. Lastly, when the whole is reduced to a thick, creamy-looking liquid, give a final stir, and pour the mixture into your tray, which you will have placed ready to receive it.

Most likely a number of air-bubbles will be floating on the surface of the liquid. These you must get rid of at once, or you will never be able to get off a clear and neat impression.

This part of the business is very easily managed. All that you need do is to heat your needle to a red heat, and touch each bubble in turn with the point. This treatment will cause them to burst, and by the time you have destroyed them all the composition will begin to set. For the next half-hour you must leave it perfectly undisturbed, upon a level surface, and at the end of that time it will be ready for use.

If all has gone well, your graph ought now to present the appearance of a pale yellow slab, yielding and rather clammy to the touch, and with a peculiarly glossy surface. This gloss will vanish after you have taken off your first impression, but that you need not trouble about.

When you wish to make use of your machine, write your letter or circular, or whatever it may be, with the special ink, and take care to make the up and down strokes as nearly as possible of the same thickness throughout. Let the writing dry, without blotting it, and then lay the sheet of paper face downwards upon your graph. Take care that in so doing you get no air-bubbles. If you do the result will be an uneven impression.

Now rub lightly with your finger over the whole of the paper as it lies upon the graph, in order to make sure that every part shall be in actual contact with the composition. Then, after about a minute or so, remove the paper very carefully, lifting it by one corner, and you will see that a reversed copy of the writing—a ‘negative,’ in fact—remains upon the graph.

Without loss of time take another sheet of paper, lay it upon the writing, rub as before, and remove after four or five seconds. An exact copy of the writing will by that time have been transferred to it, and by repeating the process you can take any number of impressions, up to fifty or sixty, that you may happen to want. As soon as you have printed off a sufficient quantity, wash your graph with cold water, rubbing lightly with a piece of clean rag until the writing has almost disappeared. Then dry, and put away until again required for use. If you leave it for any length of time before washing, the ink will sink deeply into the composition. This will not matter once or twice, but if you make a practice of allowing it to do so your graph will in course of time be simply saturated with the ink and will assume a deep violet hue.

The copies which you will have taken will probably have absorbed some of the moisture from the graph and curled up into a kind of spiral form. These you can easily straighten by means of warmth and a little judicious pressure.

After you have used it a few times the surface of your graph will most likely become rough and uneven and unfit for further service. When this is the case, cut the composition out of the tray with an old knife and melt it down afresh. When thoroughly liquid, stir it well, pour it back into the tray, and eradicate the bubbles as before. Do not melt it down in the tray itself. If you do the glycerine will rise to the surface for want of proper stirring, and utterly ruin every sheet of paper you place upon the machine, obliging you to melt down the composition over again before it can be of the least use.

After melting the mixture some fifteen or twenty times you will find it necessary to add a little water, and perhaps a small quantity of glycerine also, in order to replace that which has passed off by evaporation. Be careful not to overdo it, however, for a very slight error in the proportions of the different ingredients will render the mixture useless.

Ink you had better buy; it is cheap enough, costing only about ninepence a bottle, and can be obtained almost of any stationer. You can manufacture it yourself, of course, by making a saturated solution of one of the aniline dyes (mauveine is the most powerful), and adding a few drops of glycerine, but, so far as my own experience goes, the home-made article is never really satisfactory, and does not give nearly the number of copies yielded by that which is specially supplied. Always procure violet ink in preference to black or red. It is far more powerful, and gives better and more numerous impressions.

N.B.—If you should happen to spill some of this ink on your fingers, wash them at once, or you will not be able to remove the stain without considerable trouble.

One word in conclusion. Never put your graph away while wet. If you do, the composition will absorb the moisture, the proper proportions will be altered, and before very long you will find that the printing power of your machine will be a thing of the past.

CHAPTER XXXII.—CRYPTOGRAPH, OR CIPHER.
By a Naval Surgeon.

I do not know what first made me take to deciphering cryptograms. I do not think I have more of the Paul Pry in my nature than most of my neighbours. If, for example, I saw two lovers whispering together, or heard two people talking aloud by my side in a language which they mistakingly imagined I was not familiar with, I would put my fingers in my ears or walk right away rather than listen to a word of their secret. But seeing a letter in cipher in the ‘agony column’ of one of the dailies always appeared to me to be a kind of challenge to my ingenuity; and, at sea, I have taken the newspaper directly away to my cabin, and never raised my head from over it until I had puzzled out the cryptogram.

This would, of course, often be a work of some hours, but it passed the time away, and that itself is something to an idle sailor. Besides, there was some satisfaction in knowing that I was the only officer in the mess who could read difficult ciphers; and there was, too often, a good deal of amusement to be obtained from a perusal of these secret missives.

Thief often writes to thief, and evil-doer to evil-doer; but the letters are more often those of lover to lover, and innocent enough too—aye, and I might add ‘green’ enough, as well as innocent. Each of the two correspondents has a copy of the alphabet they write in. In this alphabet some other letter or figure is used for the real one. For example, they might put the first three letters of their mysterious alphabet thus:—

and so on through it all. Then, if they wanted to write the word ‘Cab,’ it would read ‘Rg5’ in the agony column, and who, they wonder, that has not a copy of their key, can find this out, or know that they have chosen a ‘g’ to stand for an ‘a,’ a ‘5’ for a ‘b,’ an ‘r’ for a ‘c,’ and so forth.

But simple ciphers, when one letter or figure is substituted for another, are very easily read. If I saw the following, for instance: ‘2ssx 2s 5! 2??tnpo7x gn?ts 2! W?wwsx6,’ as soon as I glanced my eye over it I should be struck with the triple recurrence of double letters. Thus, in the first word, there are double S’s, in the fourth double marks of interrogation, and in the seventh double W’s.

Then I would ask the question of myself, ‘What are the letters most commonly doubled in the English language?’ They are the vowels e and o at the beginning of words; the consonants p, r, l, m, n, in the middle of words; and the letter s or l at the end. The double letters in the word 2ssx I guess as ‘E’s.’ Well, a consonant would come before them, and what one more natural than ‘m.’ ‘Mee,’ and the ‘x’ must be ‘t.’ ‘Meet me;’ and after a little more thinking, puzzling, and conjecture, we would make out the cipher as ‘Meet me by moonlight alone, my poppets.’ Of course this would not be all the cipher; there would very likely be several words more, and this would make it all the less difficult to read.

Now take a further illustration, that presented by the ‘Language of the Restless Fays,’ as published some years ago:—

Here you have two very well-known verses written in the language of the Restless Fays. It is exactly the same as English, excepting in the forms of its letters. The Fays have twenty-six distinct positions, one for each letter of the alphabet. Now, who can read these verses? The first letter is an ‘L.’

Glancing over the verses, we find two of the same Fay that ends the first word standing together in the second word of the sixth line, and next to the first letter; they must, therefore, we think, be ‘O’s’ or ‘E’s,’ but ‘O’s’ do not often end words, so they must be ‘E’s.’ Down with them as ‘E’s.’ Our first word would now have got as far as this, ‘L . . . l e,’ the dots representing the letters still to be supplied; the second letter must be a vowel, and the double ones, therefore, consonants. Now run over the alphabet in your own mind, and see what two consonants are most likely to make sense before the finals l e. Why two ‘T’s’ would, and an ‘I’ before that completes the word ‘Little.’

Now we have four known letters to begin the battle, so we go over every line and top the Fays wherever we find them representing ‘L’s,’ ‘I’s,’ ‘T’s,’ or ‘E’s.’ But the second words of the third, the fourth, and the eighth lines are precisely the same. They are words of three letters, and they end in the Fay we call ‘E.’ Now what is the commonest word of three letters in our language ending in ‘E’? Why ‘the,’ to be sure. These little words must be ‘the’s,’ so we mark them so, and this gives us another letter, namely, ‘H.’ Then we mark all our ‘H’s’—they are but few—and go on again rejoicing; and presently our eagle eye is riveted on the first word of the fourth line represented by three Fays, one kneeling like a volunteer, the other standing on his head, and the last touching his left toe, and we are not slow to notice that the last word in the same line ends with those three foolish Fays, preceded by an ‘L.’ So the second letter of that word must be a vowel, and it is neither ‘E’ nor ‘I.’ So it must be ‘O’ or ‘A.’ But the word ‘and’—a very common one—would with an ‘L’ prefixing it make the word ‘Land.’ Hurrah! we have it then. The first word of the line is ‘and’; the last is ‘land.’ And we hasten to put down all the ‘N’s’ and ‘A’s’ and ‘D’s’ in the verses over the heads of the representative Fays as before.

Glancing over the lines we find we have got nearly all the last word in the fifth line except the first and the two last letters, thus:—. I N D N E. . The two last are the same, two mad little Fays, running apparently for their dear little lives. Now ‘L’s’ and ‘S’s’ are both common as double terminal letters; but here the S’s make sense, and the L’s would not. The word of course is kindness.

Two more new letters? Why, we are getting on. Down they go.

It isn’t difficult now to guess the words love and above, and we have Eden and sand and this clear above us. We see, too, in the verses four words of the same two Fays each. The first Fay is O, so the second must be F, because it is not N nor H.

Now I’ll go no farther with you in the language of the Restless Fays. It would only be insulting my readers if I expressed a doubt of their being able to puzzle out the absent letters in the other words, ‘. o. l d’ you would readily guess would be ‘world,’ and that would supply you with an ‘R’ for the second word of the second line, namely, ‘r a i n s’—‘grains,’ of course. And so you quickly finish the cipher:—

Though, by the way, the printers have accidentally dropped the final letter in ‘Heaven.’

You will now understand that simple ciphers can with a little experience be easily read. Just try your ingenuity on the first one you find in any daily newspaper.

Here, by the way, is a kind of cryptogram which is difficult to decipher, and in which you might write to a friend through the public prints with comparative safety. The key to it is a rectangular triangle, and you write the word you want to transpose from A to B (vide figure subjoined), the transposed word will be found at A—C. Thus, suppose we wanted to write the following sentence, which you will perceive contains nothing but the truth:—‘The Boy’s Own Paper is the best magazine of its kind, and we all dearly love it.’ Well, take your first word, ‘The,’ and arrange it in a triangle, filling it with the letters which follow naturally in the Alphabet, thus:—

The word ‘The’ thus cryptogramised becomes ‘T I G.’ Now let us form a few of the other words in triangles, all in a row to save space:—

and so on, and we would thus find that our little cipher would read thus:—‘Tig Bpav Oxp Pbrhv it tig bfuw mbiddotm,’ &c.

Now there are two things to which I wish to call your attention in this cipher: first, the primary letter of the transposed word is the same in every case as the original; and secondly, the letters are different in each word. Just observe that the ‘T’ in the word ‘The’ remains a ‘T,’ but in the word ‘Best’ it becomes a ‘W.’ The ‘I’ in the word ‘Is’ remains an ‘I,’ but in the word ‘Magazine’ it becomes an ‘O.’ In the latter word the first ‘A’ becomes ‘B,’ and the second ‘D,’ and ‘Z’ is also ‘D.’

In conclusion, let me just add that I consider cipher-reading one of the best mental exercises that any boy could indulge in.

CHAPTER XXXIII.—HAMMOCK-MAKING AND NETTING.

I.—HAMMOCKS AND HAMMOCK-MAKING.

A hammock, as most of our readers are doubtless aware, is a species of swinging bed in use at sea, and especially in the Royal Navy. Its chief utility lies in the readiness and ease with which it can be taken down, made up into a comparatively small bundle, and stowed away during the day, so as to leave the deck clear. A hammock is not at all difficult of construction, and any boy who is at all handy with his fingers should be able to make one for himself.

The hammock is made of canvas, which is suspended at each end by a number of small cords, termed clews, which are made fast to hooks in the beams.

A mattress, with the usual quantity of blankets, a pillow, etc., rests upon the canvas, which, owing to the manner in which it is hung—i.e., up to the beams—assumes an oval shape, and is really one of the most comfortable things in the world to sleep in. Its only drawback is the number of opportunities it gives to mischievous messmates to play off practical jokes upon a youngster who is making his first trip at sea.

Of course this is discountenanced in the Navy, but it is impossible altogether to prevent it; and no doubt many a victim to a slippery hitch could bear witness to the truth of this.

A slippery hitch, we may as well inform our readers, is a species of slipknot tied in the lanyard which connects the clews and the hook in the beam. It appears all right to a casual observer, but when the victim gets into his hammock his weight begins to tell, and the knot slips away and precipitates the sleeper on to the deck.

Then, again, there was the custom, which we hope and believe has gone out of fashion now, of ‘cutting down,’ which was effected by applying a sharp knife to the lanyard, and letting the sleeper down, generally head foremost.