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 199
so be observed that the centre point is a needle,held by a small screw, in a socket formed in the leg of theinstrument. This arrangement affords a means of adjustmentas to length, whilst the point can easily be replaced if acci-dentally broken. Compasses of the larger size are sometimesmade with… … Flg. 14. size and strength, isless liable to injury.Both legs of the bow-pen compasses arejointed. Fig. 19 is afront elevation of aninstrument preciselysimilar to the last, ex-cept that it has a pen-cil instead of a pen.These compasses re-quire to be adjusted to any desired radius by the direct…
