Before this the proofmaster often tested the burning time of powder by reciting the Apostles' Creed for time measurement. The problem was that precise burning times required precise time measurement and recording, which did not appear until 1672. These early time fuzes used a combustible material that burnt for a time before igniting the shell filling ( slow match). In 1596 Sebastian Halle proposed both igniting the bursting charge by percussion and regulating the burning time of fuzes, this was considered visionary and nothing much happened until 1682.
Early reports of shells include Venetian use at Jadra in 1376 and shells with fuzes at the 1421 siege of St Boniface in Corsica. Solid cannonballs (“shot”) did not need a fuze, but hollow balls (“shells”) filled with something, such as gunpowder to fragment the ball hopefully on the target needed a time fuze. Therefore, the terms ‘percussion’ and ‘airburst’ are generally used here unless ‘time’ fuzes are being explicitly described. However, by the 18th century time fuzes were aimed to function in the air and in the 1940s proximity fuzes were introduced to achieve more precisely positioned airburst. Munitions fuzes are also used with rockets, aircraft bombs, guided missiles, grenades and mines, and some direct fire cannon munitions (small calibre and tank guns).īroadly, fuzes function on impact (percussion fuzes) or at a pre-determined time period after firing (time fuzes).