The action of the machine is as follows:  Assuming the engine to be in condition for starting, the sides of the combustion chamber, D, are red hot, the chamber charged with air, and the spray of creosote, injected by the pump, F, is ignited; the expansion of the gases produced by the combustion acts upon the bottom of the piston, B, forcing it to the top of the cylinder, and thus, by intermediate mechanism, causing the crank shaft to revolve.  By the same stroke a charge of air is forced by the compressor, C, into the receiver through the pipe, R. The cylinder is, of course, single acting, and on the down stroke of the piston, B—­which falls by its own weight and the momentum of the fly wheel—­the exhaust gases are forced through the regenerator, E, which absorbs most of their heat; they then pass through the exhaust valve, placed immediately under the feed valve, M, along the pipe, Q, up through the pipes, T, fitted into the receiver, V, down the pipes, T, fitted into the saturator, Y, and out of the funnel fixed to the bottom of Y.

[Illustration:  Fig 3.]

[Illustration:  Fig. 4.]

The charge of air for supplying the combustion chamber is forced by the compressor, C, through the pipe, R, outside the tubes, T, in the chambers, V and Y, along the pipe, P, through the feed valve, M, and the regenerator, E, into the combustion chamber.  In its passage from the compressor, it first picks up the residual heat of the exhaust gases in the tubes, T, and finally the heat absorbed by the regenerator, E, thus entering the combustion chamber in a highly heated state.  Having described generally the passage of the air from the compressor to the working cylinder, and back again to the funnel, we will now describe the details.  The working cylinder, A, is fitted into the casting which forms the water casing, K, a space being left between the bottom of the cylinder and the casing, which is filled with a non-conducting mixture of asbestos to protect it from the heat of combustion; the bottom of the piston, B, has a similar protection, and the regenerator has a lining of the same mixture, to prevent any heat from escaping through the casting which holds it.  The water in the casing, K, and in the piston, B, is supplied by a small pump, G, which forces the water through the pipe, P4, into the telescopic pipe, L either into the piston, B, or through the pipe, P6, into the casing, K—­the bottom of the casing being connected by the pipe, P10, with the auxiliary boiler, W. The steam generated in the casing, K, is carried to the boiler, W, by the pipe, P3, and from the boiler it passes along the pipe, P2, through the valve, A2, into the chamber, V, thus giving up its heat to the incoming air, with which it mixes.  The vapor gradually condenses at the bottom of the vessel, Y, and the water so formed is drawn by the pump, J, along the suction pipe, P9, and forced through the pipe, P8, back to the chamber, Y, through the valve, A1, and