Plate taken from the 'Illustrated London News'. The instrument used to measure the speed of the misile was a chronoscope, invented in Belgium by Navez. A pendulum arrangement received electrical pulses when the projectile broke the first wire and the angle which it swung could be used to measure the speed of the projectile. An example of the chronoscope used by the Royal Artillery Officers at Woolwich is part of the collection at the Science Museum.
© Science Museum / Science & Society Picture Library