1099. Aucoc, J. Jan. 23, 1907, [date applied for under Section 91 of Patents &c. Act, 1907]. Gas and explosive-vapour engines, starting. In starting internal-combustion engines by compressed air, a compressor E supplies a reservoir F, from which air is led to the engine, through a pipe f, piston valve G, and pipe H, and to a distributor I, through a branch pipe h. The valves, admitting compressed air to the cylinders A, B, C, D of the four-cylinder engine, are each formed with a piston 2, which may be without packing, or may have piston rings, or cup-leather or other packing. An annular passage 4 in the distributor is connected to the reservoir, and four chambers radiate inwardly therefrom. Pistons 5, bearing on a cam-plate 6 fixed on an engine-driven shaft 7, moves in the chambers, each of which is connected by a,pipe a, b<1>, &c. to a separate valve box on the engine cylinders. When a depression 6a in the cam-plate allows one of the pistons 5 to move inwards, air pressure acts on the underside of the valve piston 2 and lifts the valve, so that compressed air is admitted to the cylinder. When the cam - plate is rotatable, the underside of the valve piston is opened to the atmosphere through a groove 9 in the piston 5, and the valve closes under the action of a spring 3 and of the compressed air on the top of the valve piston. To turn the engine so that the distributor pistons are in a workable position, a pedal 10, Fig. 8, acts on a pawl 31 to engage teeth cut on portions of the engine fly-wheel 34, or on a disk on the engine shaft. When the pedal is depressed, air passes from the reservoir to the pipe H, while during the normal working of the engine, the valve boxes and pipe H are connected to atmosphere through a hole 11 in the valve G. To prevent the pressure in the reservoir from rising excessively, compressed air from a pipe 14 acts first on the small end and then on the full area of a piston 12, holding open the suction valve 19. The compressed air may pass on to act on a piston 21 to disconnect the driving- clutch 23. When the pressure falls, the piston descends and connects the pipe 20 to atmosphere. The pistons in the distributor may be arranged along a hollow cylinder, or may be set radially, in which case they may be made in two diameters ; or the piston may act on a face cam, Fig. 9, the connexions to the valve boxes entering at passages 8. The Specification, in the original form, as open to inspection under Section 91 (3) (a), comprises also the use of the distributor shown in Fig. 9 to send compressed air directly from the reservoir to the engine cylinders, the pipe H and grooves 9 in the pistons 5 being dispensed with, and the valves a, b, &c. being replaced by simple automatic spring valves. Further, if the valve pistons have a slight permanent leakage, it is unnecessary to send compressed air from the distributor to the underside of the valve pistons, the closing of the pipes a<1>, b<1>, &c., when the leakage past the pistons balances the pressure on the two sides, being sufficient. In this case also, the piston 5 may be replaced by a rotary, circular, or like valve, having a groove or port which puts the bottom of the valve pistons successively in communication with the atmosphere. This subject-matter does not appear in the Complete Specification as accepted.