Modern instruments and methods of calculation : a handbook of the Napier Tercentenary Exhibition (1914)
Horsburg, E. M. (Ellice Martin), Napier Tercentenary Exhibition (1914 : Edinburgh, Scotalnd) · London : G. Bell · leaf 105
hner arrangement was, that positiveoperations could be carried out by turning the handle to the right andnegative ones by turning it to the left, an arrangement which seems natural,while in the Thomas system the moving of a separate lever from addition tosubtraction and vice versa has to be carried… … Fig. 8.—The Setting Mechanism.
