[Instrumental] Engines that run on petroleum fuel are used in vehicles and stationary plants everywhere. [Instrumental] This is the two-stroke diesel engine. Blue air is compressed on the right, outside the cylinder. Fuel injection, self-ignition in the cylinder. Red exhaust gases driven out on the left. Here, the reciprocating action of a piston turned into rotary movement by a crankshaft. A rather cumbersome process preventing really smooth running. But a very high compression ratio, achieving a good thermal efficiency. And here, in the gas turbine, the compressor absorbs much of the power developed. The fuel consumption is high, the thermal efficiency low. But the engine runs smoothly because of the simple single rotary moving part. An engine can be evolved that has a high compression ratio, simple moving parts, and is free from vibration. Using two similar two-stroke engines, make an opposed piston engine. Better balanced than before, but still a complexity of crankshafts and connecting rods. Try removing them. Springs might do for returning the pistons to the center. But air cushions work better. Having got rid of the crankshafts, we must take the power from our engine in the form of hot gas, which we can use to turn the blades of a turbine. Our engine is thus a machine producing hot compressed gas. A gasifier, in fact. And so we can dispense with the turbine's compressor and combustion chambers, and leave the gas onto the blades of the turbine. Let us try and do without the auxiliaries. The air needed to scavenge the cylinder came from an outside blower. Put back the pistons, but reshape them. Surround the cylinder with a jacket, lose the blower, lengthen the injector, and put back the air cushions. Now let's insert simple automatic valves, which open and close with differences of pressure. Here, and here. Air from outside can be drawn in through the suction valves by the reshaped compressor pistons. The suction valves close. The air is compressed, forced through the delivery valves, and stored under pressure in the jacket surrounding the cylinder. When the pistons are moved outwards again, the suction valves open. If holes are put around the cylinder where the inlet from the blower used to be, the store of air will expand into the cylinder at the right moment to scavenge it. This time, when the pistons return, some of the air is trapped in the cylinder and compressed. Fuel is injected, combustion takes place, and a fresh supply of compressed air scavenges the cylinder. The gas leaves the gasifier in a series of pulses. To improve the scavenging of the cylinder and smooth the gas flow to the turbine, we form in the exhaust a large chamber called a gas collector. The cool air mixed with the combustion gases reduces the temperature of the turbine blades. Now we have a perfectly balanced engine with a high thermal efficiency, which can run on a wide range of fuels. Now, let us look at the engine itself. This one is on test. Starting is effected by first maneuvering the pistons to outer dead point by means of a small air-operated piston. A charge of air is released into the two cushion cylinders, bouncing them inwards and starting the cycle. [Instrumental]