Today almost nobody's interested in the lowly vacuum tube except vintage guitar fiends and fans of high-end stereo equipment. Back in the early 50s, they "cut through the unknown like a rocket through the stratosphere," powering everything from TV sets to early computers. IBM and pioneers of the computer industry loved them because they were faster than electromechanical relays. But tubes also took up a lot of space and threw off a lot of heat—hence the giant size of this early Electronic Calculator.