I think when the book was written, digital computers were the latest tech and analog computers had been actually pretty common for 30 years. Technology included fluid ( https://www.sciencemuseum.org.uk/objects-and-stories/how-does-economy-work), mechanical (https://en.wikipedia.org/wiki/Kerrison_Predictor) and electronic.
I don't think the title was related to the analytical engine, my take would be that it was just an encouragement to the reader that it was an achievable and usable device. It may be that the military uses contributed to the lack of public documentation of the mechanical systems. On Sun, Jul 21, 2024 at 9:03 AM Dave Wade G4UGM via cctalk < cctalk@classiccmp.org> wrote: > > > -----Original Message----- > > From: Tony Duell via cctalk <cctalk@classiccmp.org> > > Sent: Sunday, July 21, 2024 5:42 AM > > To: General Discussion: On-Topic and Off-Topic Posts < > cctalk@classiccmp.org> > > Cc: Steve Lewis <lewiss...@gmail.com>; Tony Duell > > <ard.p850...@gmail.com> > > Subject: [cctalk] Re: the 1968 how to build a working digital computer > > > > On Sun, Jul 21, 2024 at 3:08 AM Steve Lewis via cctalk < > cctalk@classiccmp.org> > > wrote: > > > > > What I meant was that in the title of the book they use "digital > computer" > > > and I wonder if there was ever a book describing a mechanical "analog > > > computer" - and what they might even look like. > > > > There have been mechanical analogue computers and I have at least one > book > > describing them on my shelves. > > > > Typically they used disc integrators with an igenious arrangement of > strings and > > drums as a torque amplifier. These were then coupled by gearing which > had to > > be set up for each problem (simple gear trains correspond to fixed gain > > amplifiers, differential gear trains to differential amplfiiers, etc). > > > > I doubt you could make one from cardboard, but there was at least one UK > > University that made a simple one from Meccano (similar to Erector Sets > across > > the Pond?). It was on show, not operating, in the London Science Museum > at > > one time, but I think it's in storage now, > > Several people have made Analog Computers from Meccano. The "first" I > think was at Manchester University in the UK intended as a prototype or > proof of concept it was later replaced by an engineered device. > Both were on display in the Science Museum but I believe they are now in > Storage. Cambridge University UK also had a Meccano Analog Computer. I > believe this is the one now on display at MOTAT, Aukland, New Zealand > > https://motat.nz/ > > there are some pictures of it on my one drive (if it asks you to sign in > and you don't wish to use an incognito window) > > https://1drv.ms/f/s!Ag4BJfE5B3onlsxny71p3CPOQV4svA?e=aSdamK > > in more recent times Tim Robinson built one... > > https://www.meccano.us/differential_analyzers/robinson_da/index.html > > .. so there are some clues on how to do it about, but no book as far as I > know > > > > > -tony > > Dave > G4UGM > >
