[78-L] Record collecting

[Don Cox]

On 31/12/2012, umashankar wrote:

> as a kid of ten, I built something like that. a gramophone spun by a
> falling wait. I controlled the speed simply by letting the string run
> through my fist, tightening and loosening it. the weight fell from the
> first floor to the ground and I could play half an lp with it.
> 
I think the falling-weight drives that were used in the 1920s also used
friction to control the speed, but the friction was determined by a pair
of spinning balls, as used by James Watt for steam engines. But this
device was not known until the Renaissance.

In your case, your brain detected any change in pitch and altered the
friction to suit, so you were in a feedback loop. 

Regards
-- 
Don Cox
doncox at enterprise.net