Historical perspectives - The Moniac A Hydromechanical Analog Computer of the 1950s

The Moniac, or Phillips machine as it is more commonly known is unusual, perhaps unique, in the world of analog computers and simulators in employing hydraulic components to simulate dynamic systems, rather than electrical or mechanical devices. While the machine may seem quaint to us now, it is difficult to imagine that any other contemporary simulator would have been quite so successful in directly demonstrating the dynamic behavior of an economic system both to students and professional economists. This article aims to bring wider attention to the machine while emphasizing the relationship between Phillip's work and control engineering