Cylindrical Slide Rules & Calculators

Otis King Model L


Otis King's Patent Calculators were made by Carbic Ltd of 4 Dundonald Road London SW19.

The following notes are from the instructions - The Holder Scale for the Model L is similar to the Holder Scale on Model K.

The cylinder carries two scales, of which the upper one is identical with the Holder Scale and operates with it for multiplication and division etc:. There being no Middle Unity on this scale, when calculations of this nature are performed on the Model L, the Unity (one) at the top or bottom of the scale, as may be necessary, is used in its place.
The lower scale is graduated from 0 to 1, in 2000 equal divisions of 0.0005 each. This is used in conjunction with the Holder Scale to give direct readings of the logarithm of any number, by means of which roots and powers are obtained.

Weight 215gm. Extended length 26cm.



OK L  Full length
Scale 430
Scale 429