Cornell’s Calculator in a Book

Some of the most fascinating items in my History of Computing collection are the one-of-a-kind, undocumented ones. The latest such addition to the collection is a calculator hidden in a book-like case, that has no mention anywhere that I could find.

This is Charles Cornell’s F.24 aerial photography planning calculator, and you can read all about it in my latest article. Enjoy!

Cornell's F.24 Aerial Photography calculator

1 Response to “Cornell’s Calculator in a Book”


  1. 1 Preston L. Bannister

    On dating the device, I would offer a different interpretation.

    If you were to go to the trouble of building such a complex instrument, you want it to last a while. So I would interpret the minimum and maximum speeds supported a bit differently.

    If no airplane reached the maximum speed covered before 1922, I would guess the calculator was constructed *before* 1922 (and likely before 1920).

    Is there a minimum speed covered? How does that compare with the cruising speed of aircraft used for aerial photography in WWI?

    My guess is that this was built between WWI and 1920.

    Two items of interest:

    The First Aerial Photography Class At Cornell University, 1917
    https://througheagleseyes.wordpress.com/2013/04/15/the-first-aerial-photography-class-at-cornell-university-1917/

    World War 1 Aircraft Ranked-by-Speed (1914-1918)
    http://www.militaryfactory.com/aircraft/ww1-aircraft-ranked-by-speed.asp

    Where does 100-150 mph fall in the calculator’s range?

    My first guess is the calculator was made by member(s) of the Aerial Photography class at Cornell, between 1917 and 1920.

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