The concept of using sound to determine the depth of a lake or ocean was first proposed in the early nineteenth century by the French physicist Francois Arago (1786-1853); however, for nearly a century little research was conducted on the subject. Interest in underwater ranging was renewed in 1912, when the luxury vessel Titanic collided with an iceberg and ruptured. Experimenters then began to use supersonic waves in an attempt to detect submerged obstacles, but the majority of the scientific world was not committed to this research until two years later. On September 22, 1914, in less than an hour, a single German submarine sank three British cruisers carrying more than 1,200 men. In order to defend themselves against this new weapon, the British government funded a tremendous effort toward the creation of an underwater detection system.

At the time, the best idea concerning such a system came from the Russian engineer...