This is the tube to be fixed in the nozzle, for the front lens tube to slide in, to regulate the focus. Round this little tube, half an inch from the edge, mark a line.
Now we will get on with the stage. For this you will use your stout tin. Take one of the plates and mark on it a piece five inches by eight, being very careful to make it quite square at the corners. Cut this piece of tin out. Now draw a line across each end at half an inch from the edge, and another line an inch and a half from the edge (Fig. 4). Cross the middle portion by lines drawn from opposite corners, and with your compasses mark a circle three inches and a half in diameter. Cut out this circular portion, being careful not to bend the plate; but if you do you must straighten it again with a piece of wood, bend the ends down along the inner line till they are at right angles with the other part of the plate (Fig. 5). Now bend the tin outwards along the other lines till it is at right angles to the other part (Fig. 6). Punch two holes about an eighth of an inch wide in each of the turned-out parts. These holes are to screw the stage to the lantern by. Next you must get two pieces of clock-spring about a quarter of an inch wide and four inches and seven-eighths long. Bend them into bows about an inch high, and turn the ends outwards a little (Fig. 7). Solder these into the inside of the stage by the middle at the top and bottom of the hole (Fig. 8). Cut another piece of tin seven inches and seven-eighths by seven inches and a quarter, and cut a circular hole in the middle four inches in diameter. Mark a line across each end an inch and an eighth from the edge, and bend the plate at right angles at each end. This is to make the spring clip to hold the slides; it is put inside the stage, resting on the springs, and with the turned-out parts outside (Fig. 9).
In cutting the tin for the next part, you must be careful to keep the sides and angles square; also in bending it into a tube and soldering it. Mark out on your tin plate (stout tin) a piece eleven and a quarter inches long and four and one-eighth inches wide, turn this into a tube by bringing the shortest edges together round a bottle, lap them a quarter of an inch, and solder the joint; now very carefully turn out one edge all round, one-eighth of an inch, being careful not to disturb the round. This can be done against the edge of a flat-iron by gently tapping with your small hammer. Cut out a circular piece of tin three inches and a half in diameter, and in the centre cut out a circular hole exactly the size of the small tube the lens-tube slides in; pass this tube half way through this hole, and solder it in, being careful that it is squarely in; now put this piece into the end of the large tube, not the turned-out end, so that the side that is soldered is inwards, and solder this on the inside of the tube. Next solder this tube, which is the nozzle of the lantern, on to the outside of the stage, being careful that the holes in the stage and tube correspond. You had better strengthen the stage by soldering corner pieces in where the turn-out parts are (Fig. 10). Now the stage and nozzle is ready to be screwed into its place on the front of the lantern, being careful that the centre of the holes are all in the same straight line; but before screwing it on, all the tin visible must be blackened with dull black paint, which I will tell you how to make at the end of this section. The inside of the lantern must also be painted with this black paint, as well as the inside of the front lens-tube. In this tube there must be what is called a diaphragm. To make this, take a piece of thin tin an inch and a quarter wide, and long enough to go round the inside of the lens-tube; solder the edges together, and close the end with a circular piece of tin with a circular hole in the middle of it a little less than half an inch in diameter. Blacken this and push it into the tube, so that the little hole is about half-way in. The lens-tube is to be pushed into the nozzle with the lens inside. To make the chimney, take a piece of tin six inches wide and nine inches and three-quarters long, bend it into a tube, and lap a full eighth of an inch; solder up the joint; then cut four notches in the top about three-quarters of an inch deep (Fig. 11).