"I speak your weight" weighing machines

"I speak your weight" weighing machines were quite common in the 50s and, I think, the 60s. You could often find one in a station and sometimes in a larger chemist.  The words "I speak your weight" were clearly visible and they did exactly that - you stood on one, you inserted your penny (? - might have been more) and after a very short while, your weight was spoken - stones and pounds of course, no metrication back then. The machines were quite large - the speaking was not electronic or digital and there must have been some weird and wonderful mechanics to select the right piece of recorded (probably on disc) voice. They were seen as quite cutting edge and there were many jokes, for example, where an overweight person got on to a machine and the machine made a derogatory comment.