Southern Gas Assoc Analog National Historic Mech Engineering Landmark Plaque?

Description

Brass colored placard, measuring 3 & 3/4" square.  Titled "National Historic Mechanical Engineering Landmark - The Southern Gas Association Analog, San Antonio, Texas 1955". The body of the plaque reads "The SGA analog was commissioned by the Pipeline and Compressor Research Council to help design safe compressor systems, free from damaging pulsations. It has been used  in thousands of designs worldwide. Analog computers predict physical behavior by simulating it in analogous processes instead of solving equations. This analog uses electricity flowing through coils, capacitors and resisters to model the fluctuating flow of compressed fluids, Its is remarkable for being used long after other analogs were replaced by digital computers. Its long survival testifies to excellent Engineering and makes it unique among analog computers"  Issued by the "The American Society of Mechanical Engineers -1990".
Plaque is still sealed in the original plastic wrap. The backside has a thin layer of cork (to protect against scratching a desk, as this appears to be an award of some sort. I guess it could be a brass coaster?)
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