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Hi Francis,

So close!  I have been lurking in respect to the re-created cylyndrical slide rules and hoping that I'd see a Sine or Cosine scale along with the equivalent "D" scale from a 10" slide rule.

I saw your "Fuller Scale", it seemd to approach "1" at both ends of the Fuller scale, and I thought my wish had been granted for a 31 foot slide rule.

Alas, it's just close.  So far I haven't been able to figure how it is so close without being 100%. I know that the Sine and Fuller scales would be wrapped around different size cylinders so I took the centerline of both and took the distance from the bottom edge of the sine scale to 14_12 and to 22_50.3.  I then tried all combinations of measuring up and down to the centerline mark on the Fuller scale and I can't get the correct numbers.

Sine 14_12 by calculator is .2453.  Sine 22_50.3 by calculator is .3881.

On the Fuller scale I get 2456 and 3893.  Those are respectively 5 mm and 7 mm off of the correct readings.

I tried the same along one edge with 37_00 and got 6032.  By calculator Sine 37_00 is .6018 or about 10 mm off.  All reading are off to the same side. It's almost like i should index off one side of a tapered pointer and read off the other side.

Do you know what the Fuller scale represents?

Best regards, Noell