Tuesday 10 March 2020


Anecdotally in order to bypass the intermediary services of a human operator whom the inventor suspected of siphoning off his primary business by diverting calls to her husband, a competing undertaker, tinkerer and mortician Almon Brown Strowger of Kansas City, Missouri patented an electromechanical stepping switch telephone exchange system—a uniselector that allowed subscribers to dial numbers directly, the electric pulses cycling through to the desired number—on this day in 1891.
Due to this set up, the Strowger switch is also known as a step-by-step (SXS) switch and was coincidentally granted exclusive licensing rights on the anniversary of the first convincing public demonstration of telephony fifteen years earlier by Alexander Graham Bell, whose principle was inspired and informed by the water microphone and harmonic telegraph prototype of Elisha Gray who in turn owed his discovery to a long line of innovations. Selling the rights to replicate his engineering, Strowger’s invention saw the proliferation of the many automated exchanges run by independent municipal telephone companies in the US and UK with the decade.