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 102
bears at its upper end the figure disc.In the position represented in the diagram the figure disc will turn in apositive direction, i.e. the digits will appear in an ascending series at anindicator hole situated above it. If, however, the bevel wheels slide so thatthe other one engages the vertical… … Fig. 2. will press the nose-shaped end of the lever (10) backwards. The lever (10)operates in turn on one end of the lever (11), which is pivoted in the middle,the lower end of which is fork-shaped and fits with this fork into a notch inthe sliding rod (12). The latter is kept in whichever position…
