ROPLEX

This machine works just like a straight slide rule. The circular slide introduces different ergonomics and is more compact than a straight rule.

It has two sides:

On the front:

The dial is divided into three zones occupied by the following logarithmic scales:

Starting from the periphery: n: number (about 35cm long)
n²: square
1/n: reciprocals of numbers

The scale of numbers is divided into two parts: one fixed and one mobile.

On the back:

The dial is divided into five zones occupied by the following logarithmic scales:

Starting from the periphery: n: cubes
S: sine
L: logarithms
T: tangents
S and T: sines and tangents for small angle