The need to calculate trajectories for artillery led to the quest for methods of computation more efficient than rooms full of clerks performing calculus and arithmetic with paper and pencil. Mechanical calculators such as the famous Friden calculator were used during World War I by the ballistics and ordnance engineers of all combatants. During World War I, banks of inter-linked electro-mechanical relays and, later, vacuum tubes were used to create computing machines of great, for the time, mathematical power and speed. The machines were large, expensive, power hungry and high maintenance. Business, entertainment, education and communications uses for the giant machines were not in the minds of the creators.
