The Museum of HP Calculators

HP Forum Archive 21

 Mechanical calculator doing calculusMessage #1 Posted by Bruce Bergman on 5 Mar 2013, 11:09 a.m. Interesting video and source link here:

 Re: Mechanical calculator doing calculusMessage #2 Posted by Fred Lusk on 5 Mar 2013, 7:40 p.m.,in response to message #1 by Bruce Bergman That is a very cool machine. It appears to me that the machine is doing a Simpson's Rule integration by measuring the lengths of numerous fixed width strips, then adding the areas together. As a civil engineer, I have used planimeters for years. A polar planimeter integrates polar coordinates. It's roughly similar to using an infintesimal application of the double meridian distance method of finding areas, except using polar coordinates instead of rectangular coordinates. http://en.wikipedia.org/wiki/Planimeter

 Re: Mechanical calculator doing calculusMessage #3 Posted by Lode on 6 Mar 2013, 2:57 p.m.,in response to message #1 by Bruce Bergman You should see this one! http://www.youtube.com/watch?v=s1i-dnAH9Y4 It's 41 minutes long and entitled "Mechanical Computer - Basic Mechanisms In Fire Control", and it's a 1960's military educational movie about mechanical computers aboard ships for fire control. They explain how everything happens analogue with mechanical parts: addition, multiplication, 2D functions, etc... I found it extremely interesting.

 Re: Mechanical calculator doing calculusMessage #4 Posted by LHH on 6 Mar 2013, 9:52 p.m.,in response to message #3 by Lode Absolutely fascinating. I now have a much better understanding of mechanisms I have seen over the years including this one (photos). In high school I worked summers for a surplus dealer who gave me all the leftovers from an aircraft navigational computer for salvaging all the transmitters, receivers and resolvers which he could resell. I've treasured all the pieces (many gears, bearings, differentials, etc.) and have wished I could find one of these intact someday just to display in a big bell jar or something. Incredible design and engineering!

 Re: Mechanical calculator doing calculusMessage #5 Posted by Les Koller on 8 Mar 2013, 7:24 p.m.,in response to message #1 by Bruce Bergman That was friggin' awesome. 1st time I've ever seen one of those. If I ever thought about it I would think they just estimated. Thanks for sharing!

 Re: Mechanical calculator doing calculusMessage #6 Posted by Thomas Chrapkiewicz on 10 Mar 2013, 11:04 a.m.,in response to message #1 by Bruce Bergman Curious - but it is performing a numerical approximation - not calculus. TomC

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