Feedback control: an invisible thread in the history of technology

The history of technology combines engineering with economic, social, and political factors. Technology seems to advance in waves. Small advances accumulate slowly until a critical level of technological success and economic advantage is achieved. Throughout technological history is found the idea of feedback control. Like all ideas, feedback control impacts technology only when it is embodied therein; it is not tied to any specific innovation or invention. The article describes innovations that either use feedback control or allow it to be exploited. They are simple but their impact on technology is profound. It is shown that they played a crucial role in facilitating the truly great waves of technological and scientific development. They are the escapement (a significant part of the paper is about mechanical clocks), the governor, the aileron, the gyro, and the amplifier.