You had better begin by soldering into the bottom of the cylinder the end of the steam-pipe, which you have already fixed upright in the middle of the dome of the boiler, taking care that it stands squarely across the pipe, or your cylinder will not be upright. Then place the boiler in position, and you may fix it by turning out slightly the ends of the legs, and putting a tack through, or screwing, if the bed-plate is of iron,—or with help of Baker’s fluid you can solder; but this is hardly safe work, and you had better have a wooden plate, covered with tin, and tack down the legs. I have drawn you a circular lamp, and given three and four legs to the boiler-stand; but take care that you so arrange size of lamp and openings of the stand as to enable you to withdraw the former for trimming and filling. Now fit in the two small pipes, previously bent as required. To bend them, if hard soldered or brazed, fill with melted lead, and then bend; after which melt out the lead again. If soft soldered, you must fill with a more fusible metal. There is a composition called “fusible metal,” very convenient for this work, and well worth making, because you will often need to bend small pipes into various forms. Melt zinc, 1 oz.; bismuth and lead, of each the same quantity—this will melt in hot water; 8 parts bismuth, 5 lead, and 3 tin, will melt in boiling water. You can buy these at any operative chemist’s, either mixed, ready for use, or separately. Rosin and sand are also used for bending tin pipes, the sole object being so to fill them that they will become like a solid strip of metal, and thus bend slowly and equally, with rounded and not sharp angles.
Pass the two pipes through from beneath the bottom of the cylinder, and solder them on the upper side of it, so that when the cylinder itself is added these two joints will not be visible. Then set up the cold-water cistern; block it up with anything you like so as to keep it in position, and, inserting the pipe from below, solder this also from above, i.e., on the inside of the cistern. Now, arrange the frame that is to support it, either stout wire or wood, and set it up so as finally to secure it in its place. Now, you had better set up the pump cistern, so as to secure the other small pipe in position, and prevent it from becoming displaced by any accidental blow. Fix this cistern therefore also, but leave the cover off for the present, that you may be able to solder the small pipe inside it.
You will now, at all events, have secured the position of the most important parts, and you may drop the cylinder into place, and solder this also round the bottom. This would be facilitated by turning a slight rebate, Fig. 60, S, round the disc which forms the bottom of the cylinder, so that the smaller part of it will just fit inside it; but you will be able to manage it without. Let the cylinder project a very little beyond the bottom, just to allow a kind of corner for the solder to run in; it will not show when all is fixed. Do this as quickly as you can, so as not to melt off the solder round the small pipes. Now, make the pair of A-shaped supports for the beam. Measure the height of your cylinder top, above the bed-plate, and allow about another inch, and you will get the perpendicular height to the axis of the beam. Allow 3 inches more for each side, that is, in all for each side, 3 inches longer than if it was to be perpendicular instead of spreading. Take enough brass wire, about as thick as a small quill, to make two such legs. Bend it in the middle, like T, Fig. 60, and flatten the bent part by hammering, so as to allow you to drill a hole to take the pivot on which the beam is to oscillate. If you like to flatten all of it, and then touch it up with a file, so as to get quite straight edges, it will look much more handsome. Make two such pieces exactly alike, and, at distances alike in each, put cross-bars. File a little way into each, making square, flat notches, which will just take two flattened bars of the same wire; heat them, and solder very neatly, so that no solder appears on the outside; file all flat and true. In this way you can make almost as neat supports as if they were of cast brass, and you are saved all the trouble of making patterns. By and by, nevertheless, you must do better.
As I have directed you in this instance to put a wooden bed-plate to your engine, you may point the ends of the wires, and, making holes sloping at the same angle in the wooden stand, drive the wires into them. You have an advantage here, inasmuch as you can raise or lower your stand until the position of the beam comes exactly right, and you find the ends drop over the centre of the cylinder and pump-barrel as it ought to do. When this is the case, you can cut off any wire that projects below the stand and file it level, for it will not be likely to need more secure fixing. The pump may now be soldered into the cover of the cistern (before the cover itself is fastened on), and a hole must be then cut to receive the water that will flow from the spout, and then the cover can be fitted on. There is no need to solder it, if it is made to fit over-tightly; and you may wish, perhaps, to get at the lower valve of the pump now and then.
The only thing left to do is to arrange the safety-valve of the boiler, which is in many cases the place through which the water is poured to charge it. In this engine it is, however, plain that you can fill the boiler by turning both the taps at the same time. A little will run off by the waste-pipe, but not enough to signify, because the tube below the cylinder is so much the larger of the two. The safety-valve is a little bit of brass turned conical to fit the “seat,” made by counter-sinking the hole. It is shown at K, Fig. 59, N being the seat, O P the dome of the boiler, and close to O is the gauge-tap for ascertaining the height of water in the boiler. L M is a lever of flattened wire, pivoted to turn on a pin at L,—L O being an upright wire soldered to the boiler. A notch is filed across the top of the valve, on which the lever, L M, rests. The weight is at M. One, as large as a big pea, hung at the end of a lever 2 inches long, the valve at half an inch from the other end, will probably suffice for this engine.
