Well this has certainly been an informative (and eye-opening) thread for me.
I had no idea that analogue computers were as common and as long-lived as
they were. In the only "History of Computation" course that was included in
my Comp Sci program, analogue computers were treated only incidentally, with
the implication that development ceased with the advent of digital computers
(whether electro-mechanical or electronic) in the mid 1940s. In that course
and in other computing histories I've read, analogue computers seem to be an
unfairly neglected topic.
Thanks to all.
Mark