The practical draughtsman's book of industrial design and machinist's and engineer's companion : forming a complete course of mechanical, engineering and architectural drawing (1866)
Armengaud, M. (Jacques Eugène), 1810-1891, Armengaud, M. (Charles), 1813-1893, Amouroux, M. (Jules), Johnson, William, 1823-1846 · Philadelphia : H.C. Baird · leaf 206
lever is twice as long as theother, the arc described by its extremity will be twice as great,whatever be the extent of the movement. In this case, howeverthe radii of the arcs would be uniform, and an arrangement is BOOK OF INDUSTRIAL DESIGN. 195 required, providing for the increase or decrease in… … tremities and thecentre of motion.It is necessary,however, that the outer joints ofthe lever should be maintainedconstantly parallel to each other, and it is likewise desirable that the instrument should be capa-ble of adjustment for different proportions, otherwise its scopeof usefulness would be…
