"Miles Maxted" bravely wrote to "Mike Ross" (13 Jul 04  05:09:00)
 --- on the heady topic of "Re: Relative Humidity"

 MR> There were a lot of secrets even in WWII.


 MM> Especially in WWII - my father started off on radar applications
 MM> at BTH Rugby, and ended up seconded to the occupying Canadian Army
 MM> as scientific advisor, before spending 2 years in Germany
 MM> reestablishing technology.   He passed on still refusing to tell
 MM> me how and where the solid state silicon rectifier he'd wired into
 MM> my hobby radio receiver in 1939 had come from ...   and I seem
 MM> unable to find out now;  radar receiver bits seem to be likely
 MM> suspects !

Silicon junctions have a natural log function just the right thing for
an analog calculator built up using differential operational circuits.
These were already described in the 20's and would have been a natural
in the 30's for extracting logs then adding and subracting voltages to
derive multiplication, division, squares, roots, and some trig
functions. It would have been complex but doable. I recall wiring up
an analog computer in my early tech classes. This used IC opamps and
wasn't very precise but still quite good when compared to the
alternative then of a room size digital computer or worse nothing.

 M*i*k*e

... Your user friendly program is talking to Turing behind your back.
--- Blue Wave/DOS v2.30