These slides will be too small to use in the lantern by themselves, so you will have to make a wooden slider for them. This is made as in Fig. 2.

Take two pieces of board one-eighth of an inch thick, four and a half inches wide, and eight inches long, with a square hole cut in each three and three-quarter inches square. These boards make the back and front of the slider, and are joined together at the top and bottom by two narrow strips of wood eight inches long, a quarter of an inch wide, and one-eighth of an inch thick. This slider is pushed into the slide-stage of the lantern, and the glass slides pushed into it as in Fig. 3.

The slider is rather smaller than the stage in the lantern, which allows of it being adjusted so that the centre of the picture is in a line with the centre of the lenses.

For making movable slides, such as slipping-slides, lever-slides, rack-slides, and chromatropes, you will require wooden frames.

To make these frames, get a carpenter to cut you some slips of pine or deal three or four feet long and half an inch square, with a groove running all along one side of each slip say one-eighth of an inch deep and one-sixteenth of an inch wide. Make your frames out of these slips of wood, seven inches long and four inches wide, outside measuring. Fit a glass in the groove like a slate is fitted in its frame.

Make about a dozen of these frames, and set them on one side to dry. Now cut some strips of glass three inches wide and seven inches long, and cut off one corner of each, as in Fig. 4, at any convenient angle, and then cut away the upper half of the front part of each frame flush with the glass, to allow the second glass to be pulled out about half an inch when put in position in the frame, as in Fig. 5.

Your frames are now ready to receive the design. Trace the design on the inside of the fixed glass with the effects; if it is to be a figure raising and lowering its arm, the figure must be drawn with three arms—viz., the arm that is not raised and the other arm in each position, one up and the other down, as in Fig. 6. The other glass has nothing on it but two black patches, one or the other of which covers one or the other of the arms as the glass is pulled out or pushed in.

In painting these slides, all the glass in the frame around the figures is to be blackened with the opaque black, so that all light is excluded except that which comes through the figures. When this slide is painted, varnish it and paste a narrow strip of paper on the top and bottom of the glass for the movable glass to slide on without scratching the picture.

The black patches on the movable glass are painted and varnished on the inside of the glass. To get these in the right place, place the glass in position over the picture, and when pushed in as far as it will go, mark with your black on the outside of the glass the outline of the arm that is to be covered in that position; then pull out the glass as far as it will go and mark in the same way the outline of the other arm; turn the glass over and fill in the outlines with opaque black, and on putting the glass in its place in the frame you will have a figure with its arms raised or lowered. Now put the glass in its place, and fix it there by pressing into the wood of the frame two small pins at the top and two at the bottom. In putting in these pins allow room for the glass to slide easily.

The construction of lever slides is something like that of the slipping slides, except that the movable glass is circular, and the picture on the glass in the frame is painted circular and has a background. The movable glass has painted on it only the limb that is to be moved. You can get these circular glasses cut at a glazier’s; have them three inches in diameter. Fig. 7 will explain how the two glasses are to be painted. By placing the movable glass over the fixed glass, and moving it partly round and back again, the two boys will appear to move up and down. Of course the point that the board hinges on must be in the centre of the picture. Before painting the picture, cut out a piece of thin board a quarter of an inch thick, three inches wide, and six inches long. Cut this in the shape of Fig. 8 (the dark part represents the wood). Glue this wood on to the glass inside the frame, and cut away the front edge of the frame down to the glass.

Now you can paint your picture, and while that is drying take one of your circular glasses and fit a rim—made of thin brass plate, a sixteenth of an inch thick—to it. This rim is to fit the glass tightly, and is to be a quarter of an inch wide; the ends are to lap a little, and are to be soldered together. Now cut from the same brass plate a strip two and a half inches long and a quarter of an inch wide, and solder this on to the rim, as in Fig. 9. Fix the circular glass in this rim, and on the inside paint the board and children on it, put it in its place in the circular hollow in the frame, and fasten it in its place with small pins pressed into the wood and bent over the brass rim (Fig. 10). By raising or lowering the lever the board will rock up or down.

Rack slides are very like the last description of slide, but in these the movable glass is capable of being moved quite round by a rack-and-pinion work.

IV. Revolving Slides for the Magic-Lantern, without Rack-work.
By F. Chasemore.

In my last section on magic-lantern slides, I mentioned that, although the frames for rack-work slides could be purchased, they were expensive. I have since then thought that the old-fashioned way of turning the revolving part—viz., by pulley and band—would be easy for boys to make, and answer very well if the cord is kept tight. In this section I give instructions in making these frames.

Make the outside frames five inches wide and ten inches long, out of wood half an inch by three-eighths, put edgeways. Cut a piece of thin deal or mahogany three-eighths of an inch thick and five inches square, and glue this on one side of half the frame (as Fig. 1). Cover the other half with a piece of glass four and a half inches square, and fasten it there with strips of deal, making them flush with the board on the other half. Glue corner-pieces (as in Fig. 4) on the other side of the glass, turning the frame over.

Make the circular frames out of a wooden circular box—such as a tooth-powder box—about four inches in diameter. Take off the lid and cut away the rim that it fits on, and saw the box into rings about a quarter of an inch wide, marking the box first with a pencil, and cutting through the marks with a fine saw (as Fig. 2). Have your circular glasses cut the exact size of the inside of these rings. Fix the glass in each ring so that the wood projects a trifle beyond the glass on one side. With a three-cornered file cut a triangular groove all round each ring about one-sixteenth of an inch deep.

Make the small wheel out of a cotton-reel about an inch or an inch and a quarter in diameter. Cut off the ends and cut the other part into slices a quarter of an inch wide, and cut a groove about an eighth of an inch deep all round each (as Fig. 3). On one side of each of these pieces fix a short wire about three-quarters of an inch long near the edge; this wire will serve as a handle to turn the wheel by. Fasten this small wheel to the board by a screw that fits easily into the hole in the centre, without too much play (Fig. 4). Put the circular glass and frame in its place and glue a piece of wood (A, Fig. 4), about two inches wide and a quarter of an inch thick, to the wooden half of frame. Get two small glass beads about a quarter of an inch long and an eighth of an inch wide. Put a wire about an inch long through each, and bend the wires as in Fig. 5. Sharpen the ends and press them into the edge of the wood (A, Fig. 4, B B), so that the beads will turn easily without touching the wood. Cut away a semicircular portion of the end of the frame (Fig. 4) and fasten a small button made of brass plate in it, and fasten another button to the wood (A). These buttons will keep the circular frame in its place. Connect the two wheels with a piece of strong twine, not too thick, going round them both, and fasten the ends by lapping them and sewing them together. Now if you turn the small wheel the large circular frame will turn round in the same direction if your work is well done. The edge of the circular frame must not touch anything but the glass it rests on, the two beads, and the two buttons. The view is painted on the inside of the fixed glass, and the revolving portion is painted on the under side of the circular glass. In Fig. 4 the mill and background are painted on the fixed glass, and the sails on the movable one.

Chromatropes can be made in the same way, except that the small wheel has two grooves in its edge, and the other part is made up of two revolving frames, which are turned in opposite directions by one cord passing round both and the small wheel. The lower frame rests on the square glass, and the other frame rests on the lower one. The cord is passed from the right-hand side of the lower groove in the small wheel up the right side of the lower frame, round the top and down the left side to the left side of the upper groove in small wheel, round the upper groove to right side up to the left side of upper frame, round the top down the right side of frame to left side of lower groove of small wheel, brought round, and the two ends joined. It will be seen that by putting the cord this way the two frames are turned in opposite directions, although the small wheel turns them both. Have the cord tight, and well rub all the parts that work together with blacklead.

In painting chromatropes, each glass is painted with the same pattern, and then they are placed face to face, and in turning make very elaborate and constantly-changing figures.

V. Screen Frame for the Magic-Lantern.
By Frank Chasemore.

Great inconvenience is often caused in fixing a screen in a room for the lantern, such as taking down pictures, etc.; and sometimes it is impossible to hang it without doing some damage to the walls and paint by driving nails and hooks. Even then the screen has to be put up in an inconvenient place.

By using the following contrivance all this will be avoided. The screen can be put in any part of a room most suitable for the show, and afterwards taken to pieces in a few minutes and packed away in a box thirty-six inches long and about eight inches deep and wide.

The frame, or stand, can be bought at the shops, but it is much cheaper to make your own.

The materials for this frame can be bought at a small outlay, and are—fifteen wooden rods three feet six inches long and about an inch and a quarter in diameter—the handles sold at the shops for fitting to hair broom-heads do very well indeed, and are not very dear; two pieces of wood six inches long, five inches wide, and one inch and a quarter thick; and, lastly, some stout tin plate.

First of all, take the two wooden blocks and cut them the shape shown in Fig. 1; the width at top is three inches, and at the bottom five inches. Divide the top and bottom lines into two equal parts, and draw a line from top to bottom through the points of division. On this line mark a point an inch and a half from the top, and with this point as centre bore a hole right through the wood, which hole is to be just large enough for the wooden rods to fit tightly into. Draw a line across the face of the block half way down (as in Fig. 2). Along this line, and from each end of it, mark inwards a distance equal to the diameter of the wooden rods, and do the same along the bottom line (as in Fig. 2). Join these points as in the figure; cut out the middle portion, leaving the projections three inches long and an inch and a quarter square. These projections must be rounded by taking off the corners with a sharp chisel or knife. Trim them down till they are the same size as the rods.

Now you will want your fifteen wooden rods. See that they are all the same thickness. Cut off the ends of each, to make them quite square, and making the rods exactly three feet six inches long. From your tin plate cut fourteen pieces, each piece to be six inches long, and wide enough to go round the rods and to lap about a quarter of an inch. The width can be found by rolling paper round the rod and letting it lap a quarter of an inch, and then cutting it off. Place this paper on the tin and mark the width. The tin can be cut with a large pair of scissors. Now roll each piece of tin round the rods so as to form fourteen tubes. These tubes will now require to be soldered. You can get your tinman to do this for you, or you can do it yourself. If so, the following is the way to do it.

First of all, get some muriatic acid and some clean zinc cuttings. Put the zinc into a bottle and pour over it the acid, and set it on one side for a time till it has quite done effervescing; then add a little more zinc, and if it begins again wait a little longer and add more. Do this till it does not effervesce on putting new zinc into it, when it is ready for use. You must get some solder from the plumber’s, and if you have not a soldering-bit he will perhaps lend you one; but you can buy the bits now in many shops where they are sold on a card with some solder. The cost is from one shilling upwards.

The first thing to do is to ‘tin the bit’ (or cover the face and point with solder). This is done as follows. Place the bit in the fire to get hot, but not red. Take a clean piece of tin-plate and put on it a few drops of the zinc solution, and put a small piece of solder into it. When the bit is hot enough take it out of the fire, and with a coarse file clean the face and edges of it, and place it on the solder in the zinc solution on the piece of tin. In a few seconds the solder will melt and flow all over the point of the bit. This must be done to the bit every time it gets red-hot, as in that case the solder is burnt off.

Now put the bit back into the fire and take one of the tin tubes and first clean the surfaces that lap together by scraping them with a penknife. Rub each surface with the zinc solution and lap them together, and tie the tube round with string, to keep the edges in their places. Take the bit out of the fire when it is hot enough, and place it on the end of the stick of solder, which will be melted and stick to the bit. Place the bit on the top of the lapping edges, and in a few seconds the solder will flow from the bit between the surfaces to be joined, and by drawing the bit from one end to the other it will draw after it the solder and make a strong joint. If the bit did not at first carry enough solder to make the whole joint, more can be added by applying the stick of solder to the bit while it is on the joint. Solder the fourteen tubes, and clean off the joints by scraping and filing the superfluous solder off and polishing up with a piece of glass-paper. Clean the joint inside well with a piece of oiled rag to destroy the zinc solution left inside.

Now fit a tube on one end of each of fourteen of the wooden rods. The tube must be pushed on to the wood so that it is half way, or leaving an empty space of three inches. The tube can be fixed to the wood by two or three tacks driven through the tin. The fifteenth rod has no tube to it.

This is all there is to be made for the frame. In putting it together take the rod without a tube and two others, and join them together like a fishing rod, place each end of this compound rod into the hole in one of the blocks of wood, fit together the other rods into sets of three. There will be four of them. At one end of each set will be an empty tube, these are to be fitted on the pegs on the blocks at the ends of the other rod. The frame will now be composed of two uprights, each made up of two compound rods, and these support the cross rod or screen roller.

In the bottom rod of each set bore a hole with a gimlet, as in Fig. 3, and get two pieces of iron wire about one-quarter of an inch in diameter and bend the ends at right angles to the other part, leaving this middle part about two feet long. These are to be fitted to the rods, one to each pair, by pushing the bent ends into the holes in the ends of the rods as in Fig. 3; they are to be fitted on the outside of the rods.

Fasten these two wires together by passing a cord round both and tying the ends together. Sometimes the weight of the screen will cause the roller it is hung on to ‘sag’ or drop in the middle. But by tightening the cord underneath, the lower ends of the uprights will be brought towards each other, and will raise the middle of the screen roller.

To make the screen you must get some linen. This can be bought ten feet wide. Get three and a half yards of it, and have it hemmed at the top and bottom.

The top hem must be large enough for the roller to pass tightly through. The screen will get more or less creased in packing, but will come all right on being wetted and hung on the roller.

This frame is calculated for a ten-foot screen, which will be found large enough for most rooms. But it can be made for a larger one by adding one or more rods to each of the sets. The linen for a larger screen must be joined, as it is not made more than ten feet wide. In joining linen for this purpose do not let the seam come across the middle, but add an equal piece at the top and bottom, which will leave the middle of the picture clear, and the line of the join will come among the dark features of the foreground, and will not be seen so much. The tin tubes had better be varnished over with Brunswick black, as they will look better and not be liable to rust. Varnish the iron wires also.

In packing up, the screen must not be rolled on the rods, but had better be folded up by itself in paper and placed in the bottom of the box, and then the rods put in afterwards. Otherwise the screen might have some patches of Brunswick black in the middle of it.

Fig. 4 is a view of the screen and frame when put together.

VI. Magic-Lantern for Opaque Slides.
By W. J. Gordon.

A lantern to exhibit opaque slides or ordinary pictures on paper or cardboard is, if anything, easier to make than one of the usual type. It is nothing but a photographer’s camera with the action reversed. In the camera the large well-lighted object is focussed down by the lens into the miniature copy in the darkened box; in the lantern the miniature in the well-lighted box is focussed up into the enlarged copy in the darkened room.

The essentials are, a good lens, a good light, and a well-focussed, well-illuminated picture. Any ordinary box will do. Its shape and size are of little moment, but the box must be blacked inside and have the top replaced by or covered with tin or sheet-iron. Let it be, as we have to make one, say eighteen inches long and two feet high. The depth of the lantern depends on the focal length of the lens you have chosen for it. This lens can be either a plain magnifying-glass, such as is used in cheap lanterns of the common build, or it may be compound, of the sort used in portrait cameras. The compound lens will give the best results. Suppose we are dealing with a three-inch lens having a focal length of ten inches, our box should then be ten inches deep. Very much smaller boxes with less powerful lenses can of course be made, and they will act just as satisfactorily.

The top, as we have said, should be covered with tin, to prevent its catching fire, and it should be fitted with a chimney made by bending a sheet of tin and soldering its edges together. In order that a circle of light may not be thrown on to the ceiling, a cap must be fitted over the top so as to leave ample space for the passage of the heated air. In the front of the box a tube must be fitted, just large enough to hold another tube, in which the lens is held, and by this contrivance perfect adjustment of the focus is assured.

Arrange the interior as shown in the sketches, which are so numerous and self-explanatory that lengthened description is not required. The only peculiarity is in the back, which is so made to prevent a flood of light being thrown out behind each time a picture is changed. There are two doors to it, one being just a quarter the size of the other, and having a piece of wood of the same size fixed on at right angles of it, on the same principle as is seen in many mahogany birdcages where the inside flap of the seed or water-carrier just fills the hole made for the real door when the real door is open. The slide-carrier is marked A, and when the door is shut the marked side of the shade (B) fits close up against the side of the box. The lamp is placed as shown, and should be just far enough from the lens to thoroughly light up the picture without permitting itself to be seen. A paraffin lamp is the best, and it should if possible have a round argand wick; but a flat one will do fairly well. The round shape of the wick is suggested as giving in the majority of instances the most equable light. The bottom of the door should be cut away slightly or perforated, as in the sketch, so as to allow air to enter freely, as no lamp will burn without a draught.

It is a good plan to try the chimney on the top before the top is fixed on, and then if the top is left a little larger all round than will be required it can be shifted about until the proper position of the lamp with regard to the lens and slides can be found by experiment, and all risk of failure avoided. When the correct distance is found the top should be screwed down and trimmed to shape. Inside the box, below the chimney, a ring or stop should be screwed to prevent the lamp slipping about in the event of the lantern receiving a sudden knock.

In another form of this lantern the back is in one piece, and the slides are introduced through a slit at the side, a plan, however, having a few disadvantages. The principle of the opaque-slide lantern is apparent at a glance, and once that is understood no difficulty should arise in devising many patterns of the instrument and utilising old materials for the purpose. Any pictures can be shown, coloured or uncoloured; even our own designs in this book can be thrown on the screen with good effect.

CHAPTER XXI.—HOW TO MAKE AN APHENGESCOPE, OR APPARATUS FOR EXHIBITING PHOTOGRAPHS, OPAQUE PICTURES, AND LIVING INSECTS IN THE MAGIC-LANTERN.
By Frank Chasemore.

In the last chapter there is an illustrated description of a magic-lantern for opaque slides, and as I have for some time used a contrivance on the same principle for use with an ordinary lantern, the few words I have here to say may not prove uninteresting. Like the opaque lantern, this modification of it is very inexpensive.

The interest of a magic-lantern is greatly increased by its being made to show photographs of friends or public men, and also pictures or engravings, Christmas cards, etc. This can be done by the following simple contrivance, which will cost but a few pence. Indeed, the one I use cost me only threepence, and is made out of a cigar-box; but a better and stronger one can be made for less than a shilling. It consists of a five-sided box, with top and bottom, as seen in Figs. 2, 3, and 6. In two of the sides are circular holes, and one side is left open about two-thirds of its length, which opening is closed by a door or shutter revolving on a pivot at the top and bottom, to carry the photograph. This shutter is fitted with four small clips on each side for the purpose of securing the card in its place.

Now for the construction. Get some thin board—deal is very good for the purpose; it is to be a quarter of an inch thick—cut two pieces out of it for the top and bottom, the shape shown in Fig. 1.

The dimensions of these pieces are as follows. The sides B and E four and a half inches long; the side A five and a quarter inches long; the other two sides are each to be three and three-quarter inches long. The angles where A joins B and E are each to be a right angle; so is the angle where C joins D. The two other angles are to be a hundred and thirty-five degrees each, as marked in Fig. 1. The sides of the box are to be eight inches long each, and are a little less in width than the edges of the top and bottom that correspond, so that when put together the outside of the box is flush with the top and bottom. The joints are to be glued together, and can be strengthened with pins driven in like small nails. The side E is not to be covered in all the way up, but only about two inches and a half from the bottom; but this depends upon the height that the nozzle of the lantern comes up this side when placed against it. Fig. 2 shows the opening left. When the glue is quite dry unscrew the brass focussing-tube from the lantern and place the box with the side C resting against the nozzle of the lantern, and mark round the nozzle on the side. Find the centre of this circle, and through it draw a line right across the side C, parallel to the top and bottom, and continue this line across the side B in the same way, as seen in Fig. 3. Find the centre of these two lines, and with these two centres mark a circle on each of these two sides, the one in the side B to be of a size to fit the brass focussing-tube, and the one in the side C to be about three inches in diameter, or large enough to allow the nozzle of the lantern to fit into it as far as it will go without coming between the picture and the lens, as seen in Fig. 4.

The remaining part to be made is the shutter to carry the photographs. This must be exactly the same size as the opening left in the side E, and is to be made out of the same quarter inch board. Let it be quite square at the sides and corners. The opening in the side E is to be equal in length to twice the distance of the centres of the holes in the sides B and C from the top edge of the sides where they join the top board. On each side of the shutter, in each corner, fasten a clip, as in Fig. 5. These clips can be made out of card or thin metal, cut in the shape shown, and fastened to the shutter with small screws or short pins. Mark the middle of the top and bottom edges of the shutter and place it in its place in the side E, and mark on the side the points where these marks come to. Take the shutter out again and bore a hole in the bottom edge of it about half an inch deep, and large enough for a stout pin to go into. In the lower part of the side E, and in the edge that the shutter will rest on, drive a stout pin in middle so as to form a pivot for the shutter, leaving out about a quarter of an inch, and cut off the head. Replace the shutter, fitting the pin into the hole bored for it, and drive a pin through the top board right into it, so as to form a second pivot. The shutter will revolve round these two pivots and expose the sides alternately to the lens. Fix two clips to the edge of the top board to keep the shutter in place while shut. Cover the whole of the box with unglazed black paper.

This simple little apparatus is all that is necessary to show any picture on the screen. To use it, first screw the tube carrying the focussing-tube into the hole cut for it in the side B, and push the nozzle of the lantern into the hole in the side C as far as it will go. Light the lantern and place the whole on the table so that the back of the lantern and the focussing-tube are directed to the screen, as seen in Fig. 6. Now place a photograph in the clips on one side of the shutter, and turn it round and put one in the clips on the other side. The photograph inside will be strongly illuminated by the light from the lantern, and an enlarged image of it will be projected by the lens on to the screen. The photographs placed on the shutter of the aphengescope must be, of course, upside down, as the lens will have the effect of inverting the pictures.

A strong light is required for this apparatus. The ordinary oil lamp will not show a bright picture at a distance of more than two or three feet. The ‘Triplexicon’ lamp, a lamp having three parallel wicks, burning paraffin oil, will give a good picture. But the best results are obtained from the oxycalcium and oxyhydrogen burners. These will distinctly show a large and brilliant picture, at a great distance from the lamp.

With this instrument, a watch placed on the shutter will show an enlarged image of itself, and the motion of the minute hand will be very distinctly seen. Anything that will go on the shutter will be shown on the screen. This adds greatly to the available articles to be used as slides.

Some of the most interesting slides are made by mounting entomological and botanical specimens on white cards, and putting the cards in the clips on the shutter, when enlarged images of the butterflies, moths, or beetles, etc., will be seen on the screen in all the glory of their natural colouring.

But the most interesting of all is the exhibition of living insects. This can be done in the following manner. Take out the shutter and lay it on the table: get a watch-glass, about two inches diameter, and deeply domed. Place this glass on the middle of the shutter, and with a lead pencil mark all round the glass. Remove the glass, and with a sharp knife cut into the wood of the shutter all round the pencil mark, cutting about one-eighth of an inch deep. Cut out all the wood inside this mark so as to form a hollow or well about two inches diameter and one-eighth of an inch deep, as Fig. 7. Cut the bottom of the well quite smooth, and line it with white paper.

Now get a piece of thin glass about the size of a photograph card, and thin enough to go under the clips on the shutter. Your shutter is now ready for the specimens. Replace the shutter and put a fly or other small insect into the well, and cover it with the flat glass, fastening it with the clips. Now turn on the light in the lantern, and focus the lens, and an enlarged image of the fly will be seen on the screen crawling about in a natural manner. For larger insects, such as a cockroach, wasp, etc., you must use the watch-glass to cover them instead of the flat glass. This can be fixed in its place by being pushed into the hollow or well, when the sides or walls will hold it. The two glasses are required for the reason that the insects ought not to have more room than will allow them to crawl about on the paper, as they would sometimes get on the glass, when they would be out of focus of the lens. But the glass must not be so close to them as to pinch them. You will have to keep your living specimens in boxes, with air-holes so as to have them ready for the exhibition, and will also require a small pair of forceps to handle them by, being very careful not to injure them.

On page 247 I have told you how you can make a light and portable frame for the screen, at a small cost. Lads who have experimented in chemistry ought to be able to make the oxygen gas for the oxycalcium light.

This instrument, as here described, was intended for use only with the tin lanterns as sold in the shops, which all have tapering nozzles. It can, however, be used with the lantern described in my former article, but the stage of that lantern would require to be modified in the manner shown in Fig. 8.

Unsolder the large nozzle-tube from the front of the stage, and in its place solder on a band-ring of stout tin. This band is to be one and a quarter inch deep, and the diameter just enough to allow of the back end of the nozzle-tube fitting in it very tightly when the lantern is used in the ordinary way. The small turned-out rim of the nozzle-tube must be carefully cut off for this purpose. The aphengescope itself must have a small tin tube fastened in the small hole in the front of it, for the focussing-tube of the lantern to slide in; and the large hole must be cut large enough for the tin band on the front of the stage of the lantern to fit into it. This arrangement will allow of the light in the lantern being brought closer to the picture than can be done with the ordinary lanterns, and will, of course, illuminate it more strongly.

A very good lamp, with high illuminating power, to be used in any lantern, especially with this instrument, can be bought at the paraffin-lamp shops for a small sum. The tin duplex lamp, burning crystal oil, is the best. I should recommend any of my readers who have made, or are about to make, the lantern I have described, to get one of these, instead of making the lamp described with it, as it will give nearly twice the light. An arrangement will of course have to be made at the back for the reflector. If a lamp cannot be got that is low enough for the lantern, you can make the body of it yourself. You can generally get, at these shops, damaged lamps at a small cost. Get one that is damaged only in the body. Unscrew the brass-work, as though you were about to fill it, and put it on one side. Unsolder the brass screw-socket from the reservoir. Now make a square tin box for the new reservoir, covering in the top. The box is to be an inch and a quarter deep, and as large as the lantern will allow. In the top cut a hole to solder the brass screw-socket into. Then screw in the brass wick-carrier and make the clip for the reflector.

If a pair of lanterns are used the light will be proportionately stronger, and a strong light is an important thing with this instrument.

Fig. 9 gives the plan of the top and bottom boards of the instrument for use with a pair of lanterns, and requires no further description.

CHAPTER XXII.—INGENIOUS ADAPTATIONS FOR THE LANTERN.
By W. J. Gordon.

I.—Chromatropes and Paper Fireworks.

From Mr. Chasemore’s article on revolving slides for the magic-lantern we borrow the following diagram, as showing very clearly the principle which such slides are constructed (Fig. 1).