722,706. Jet propulsion plant; gas turbine plant. SOC. D'ETUDE DE LA PROPULSION PAR REACTION. May 1, 1951 [May 12, 1950], No. 10239/51. Class 110 (3). [Also in Groups XII and XXI] A rocket comprising an ignition chamber communicating with a combustion chamber with means for introducing an oxidizer in a substantially liquid form into the ignition chamber and non- self-igniting liquid propellants into the combustion chamber, has the supply of the propellants controlled by a valve or valves operated by the pressure of hot gases arising from the ignition chamber. The rocket shown, Fig. 8, comprises three pumps 31, 32 and 33 driven by a shaft 26 through a clutch 27 controlled by a lever 28. Pump 31 supplies fuel, e.g. kerosene, through passages 35, 38 to a valve 39 urged on to its seat by a spring 40. A relief valve 41 limits the pressure in the passage 38. Valve 39, when open, allows fuel to be supplied to the injectors of the combustion chamber 2. Pump 32 supplied oxidizer, e.g. nitric acid, to a cooling channel 46 around the combustion chamber from which it is led to a valve 50 which, when open, also leads to injectors in the combustion chamber 2. A relief valve 51 limits the pressure in the passage 49 preferably to the same value as that in the passage 38. Pump 33 supplies fuel to the ignition chamber 3. When the clutch is engaged the pumps 31, 32 supply fuel and oxidizer to the valves 39, 50 which are closed. Part of the oxidizer flows into the ignition chamber 3 where it meets fuel from the pump 33 which is then ignited. The resulting rise in pressure in the ignition chamber is transmitted through the pipe 14 to the piston 56 which then opens the valve 59 and closes the valve 58. The pressure of fuel from the pump 31 acts on a membrane biased by the spring 40 and thereby opens the valves 39, 50. Fuel and oxidizer are then injected into the combustion chamber 2 and ignited by the burning gases from the ignition chamber 3. To stop the rocket the clutch is disengaged and the pumps stop. The spring 57 then closes the valve 59 and opens the valve 58. The pressure on the membrane falls and the spring 40 then closes the valves 39, 50. The ignition chamber 3 may be as shown in Fig. 1 which comprises a body 1 in which an oxidizer such as concentrated nitric acid and a fuel such as O-toluidine, triethylamine, 2,3- or 2,4-dimethylaniline, furfuryl alcohol or aniline, are introduced into the chamber through helical ducts 6, 7 which increase in cross-sectional area in the direction of flow. A restriction 10, the diameter of which is greater than the maximum diameter of the envelope 9 enclosing the ducts 6, 7, is placed between the space into which the ducts discharge and the reaction chamber proper. A modified form of ignition chamber 3 using benzene, kerosene, an alcohol such as methanol or ethanol or mixtures thereof, as a fuel and concentrated nitric acid as an oxidizer is also described. In a further form, the fuel is a solid and cast on the walls of the ignition chamber and the oxidizer only is introduced into the chamber. In this arrangement the fuel may be an aromatic amine such as 2,21-dimethyl benzidine, 3,3<SP>1</SP>-dimethyl benzidine, or p-toluidine, or a mixture thereof. The oxidizer in this case is concentrated nitric acid. An expendible form of rocket shown in Fig. 9, comprises an annular tank 63 for the oxidizing agent in which there is located a fuel tank 64. Apparatus 67, 71 for generating gas from a slow combustion powder is also provided. When push-button 76 is closed, the ignition circuit of generator 67 is closed and stays closed even when the push-button 76 is released. The membrane 70 breaks and the oxidizing agent is put under pressure. This pressure is insufficient to break membrane 80, but it breaks membrane 78 and oxidizer flows into the ignition chamber 3 which is of the type having the solid fuel 23 cast on its walls. Ignition immediately occurs and the pressure of the gases closes the contacts 77 and energizes the ignition circuit of the generator 71. Ignition occurs in the generator 71 and the pressure of the gases breaks the membranes 72, 73, 80, 82 and the propellants flow into the combustion chamber 2 where they are ignited by gases from the chamber 3. The combustion chamber 2 has carbon walls 83 coated with a contiguous porous layer 84, the base of which may be magnesium and coated internally with a layer of metallic carbides or oxides 85. A rocket in which the propellants are supplied by pumps driven by a turbine fed with gas from gas generators similar to the generators 67, 71 is also described. In this arrangement a portion of the propellants is also used in the ignition chamber. Specification 680,717 is referred to.