On Saturday, 7 March 2020 19:51:11 UTC, Clive Arthur wrote:
On 07/03/2020 12:14, Roger Hayter wrote:

snip

I suspect the pedal design is at least twice that age, probably
somewhere between 1910 and 1930. Quick googling doesn't really give an
answer, but electric Singer machines were first made in 1910 and must
have had some sort of speed control.


The rheostat design was patented by Singer in 1949.

it was in widespread use before then

My guess is they
continued to use them for years because they had a warehouse full.

you're a wit for sure


NT