Founders of the Association convened in New York City on October 25, 1882, to devise plans and specifications for the newly organized Association. It was then that it was discussed that the Association should acquire a seal for a means of identification. This task was given to Mr. M. W. Williams with only one requirement: “The Seal of the Association shall be represented by a Full Stroke and an Expansion Card.”
The design was intended to comprise two indicator diagrams on the Seal, one of which should be a diagram from an engine taking steam for the full stroke and another from an engine with cut-off and typical expansion line. The figures on each diagram indicate the bore and stroke of each engine from which the diagrams were made. One must remember that at the time, the steam engine was common, and the indicator diagram was the certificate of engine performance, and engine performance was the dilemma engineers of that day were faced with. The ability to use and interpret the indicator diagram placed an engineer among the aristocrats of the profession. This is why the Founders of the Association chose such a seal, to show hierarchy of knowledge and professionalism.
The seal has changed little in the last century; only modernizing of the overall appearance and some word changes and updates. The seal has remained virtually the same since its conception in 1882, displayed proudly in the logo you see today.