Simms high tension magneto, 1911.
© Science Museum / Science & Society Picture Library
The high-tension magneto for igniting the explosive mixture of fuel and air in an internal combustion engine, was invented by G Honold of the Bosch company in 1903. It rapidly found favour as it combined the advantages of the magneto generator with those of the simple spark plug. This example, a Type S4 magneto with variable ignition, made by the Simms Magneto Co Ltd in 1911, is for a four cylinder petrol engine.