Before soldering on the steam chest drill two holes as at G H Fig. 10, one for the small lug G to be screwed into, which holds one end of the lever of the safety valve, and that at H should be drilled conical with a rimer, and the valve H can be turned in the lathe and afterwards ground to fit the hole with a little emery and water, by means of a slot cut across the top and worked round with a screw driver.
The spring case of the safety valve I, Figure 10, is easily made from a piece of one-eighth inch brass tubing, using some small, hard, brass wire to form the spring. When finished it should be hooked to the eye and screwed into the boiler at V.
The manhole or screwhead, K, is used to refill the boiler when it has steamed low and will have to be turned up to shape, and the bed, L, which it screws into can be firmly soldered on the boiler, having first drilled a hole slightly larger than the diameter of the screw itself, which should be sufficiently large to allow an ordinary tin funnel to be used to refill by, and the screw ought to be long enough to hold a leather washer under the head to keep it steam-tight.
The whistle, M, will require a hole drilled for it to be screwed into, and that, as also the steam-tap, N, and water-tap, O, can be bought cheap, ready to put on.
The tap O should be screwed in at a slightly higher level than the top of box B, and when working the engine should steam issue from it when turned on instead of water, you ought to immediately blow off steam by safety valve H. Then unscrew K, and refill the boiler with water.
| Fig. 17. | Fig. 18. Fig. 19. |
Fig. 21.
Fig. 22.