Oooohhh... it looped back into on-topic-ness! I believe that in actual fact, Burroughs, after a few years of night-and-day work on his mechanical calculator design, including tossing one finished prototype out a second story window in frustration, patented the *application* of a hydraulic damper to the actuator crank. His problem was that if the actuator lever was pulled down by the operator too quickly, the machine would jam very destructively. This 'bug' very nearly killed the product in the early market. He added what amounts to a small shock absorber to the crank lever, slowing it down enough so the machine could operate efficiently but not be overdriven. Then, there was no stopping it and the rest is well-known. My source is some Burroughs (Unisys) literature I gleaned while an employee of the company in the middle 80s. I bet Derrek Peschel could elaborate more on this. Now, just a sec, I wanna check my spelling, grammar, syntax, orthography, references, style, Flesch Rating, .... Cheerz D00DZ! John.