The idea of a target-influenced fuze was not new; similar fuzes for bombs and rockets existed at the outbreak of World War II. The proximity fuze functions as a small radio station in the shell’s nose. The basic components are a vacuum tube (six inches long and three inches in diameter) a battery, and a radio transmitter and receiver; a small glass tube filled with electrolyte solution acts as the battery. After the shell is fired and begins rotating, centrifugal force pushes the solution to the outside of the tube, where a chemical reaction occurs with small pieces of metal...