Curta calculator - hand-held, mechanical arithmetic

I collect antique "technology" and have a couple of these along with Comptometers, a Golden Gem, and an Odhner. It really is amazing when you look at how these things work. I also used to collect late 1800's typewriters but they were taking up too much room.

What amazes me about antique tech is that the ergonomics and the engineering were inter-meshed. Today we can put a button and a chip anywhere so the design and engineering are quite separate as long as one accommodates the other. But if you look at for example a mechanical typewriter, the entire thing is engineered to function in an ergonomic sense as well. Not only does the lever have to work, it has to require not too much force to activate, strike the ribbon with enough force to transfer ink, return to position quickly, avoid the other levers in their paths of motion, while all being arranged in such a way as to fit our big meaty hands comfortably. It truly is a lost art form.

I first read about the Curta in a Scientific American article by Cliff Stole (see scans here: http://www.leighbureau.com/speakers/CStoll/essays/Calculator... )

I am awed and inspired by this story. It helps me understand why people think a work of art is worth more if there is a story behind it. I'd love one as art for my desk (if they weren't so expensive).

Something like that would have come in handy for me a few minutes ago: I was calculating sqrt(2) to 10 places and sort(3) to 15 places, by hand on pencil and paper, and some of that got a little tedious.

I was doing this because I am relearning all the math I once knew but forgot. I'm currently finishing up relearning single-variable calculus, and I'm using Apostol's "Calculus" and doing all the exercises. One of the exercises at the end of the chapter on sequences and series of functions asks the student to derive an error estimate for the binomial series expansion of (1-x)^(-1/2), and then asks for the computation of sqrt(2) (using sqrt(2) = 7/5 (1-1/50)^(-1/2)) and sqrt(3) (using sqrt(3) = 1732/1000 (1-176/3000000)^(-1/2)) to 10 and 15 places, respectively.

Since pocket calculators would not have been available to the typical student in 1967, I decided it would be cheating to use a modern calculator or computer. I wanted to only use technology I might reasonable have had if I were a freshman in 1967. (Too bad it couldn't have been 1977, when I actually WAS a freshman taking calculus using that book...I had a nice calculator then).

Curtas get mentioned a lot because they occur in a couple of William Gibson books. But there are other nice bits of mechanical technology.

I used to work for a bus ticket machine company. The mechanical devices were amazing pieces. Really intricate and packed. I didn't work on those. I worked on "TIMtronic" (Ticket Issuing Machine electronic).

http://www.ticketmachinewebsite.com/apps/photos/album?albumi...

But see also Samuel Morland's adder, a device from 1680.

This isn't strictly relevant, but I'm curious about possible bias in that article. The line:

    His work on the pocket calculator stopped in 1938 when
    the Nazis forced him and his company to concentrate on
    manufacturing measuring instruments and distance gauges for the German army.

My gut says if this were an American or British company, the line would read "hired him and his company to make whatever else instead," but I'm willing to believe there could be a difference in the consequences to a business owner who refused to support the war effort. Anyone have any insights on this?