Imagine my delight when I received in the email, from Colin Dooley of Artis Luminis, a good quality scan of a paper scale number 423 from an Otis King's Model K, serial number W2222. Colin has his own OK pages now--check out his story of this scale.
The image here is reduced from his 300 dpi scan to only 100 dpi, so you won't have to wait forever to see it. Click it if you have the patience to see it bigger.
I interpolated the image up to 600 dpi so I would have better resolution for placing tic marks into the image at ideal computed locations, to see how well they line up with the actual marks in the image. A small section of the resulting image is shown below. The positions and the resulting image were computed using Matlab.
From the closeup image portion below, it should be apparent that Mr. Otis King did a remarkable job of computing logarithms and locations for the over 3000 tic marks, back around 1920, and reproducing them photographically since then--but he wasn't perfect. The portion shown is centered on one of the larger deviations from ideal--the tic marks for 4.65 and 4.66 (on the lower half of the scale) are off by about the width of a line, 1/100 inch or 6 pixels, while many of the marks nearby, like 4.15, 4.6, and 4.7, are pretty much right on target.
I'll try to find time to tell more of the story later...
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