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 299
ch may berotated about one extremity on the drawing board, and further, of a measur-ing roller running on the paper. This is illustrated in fig. 1, where the instru-ment is shown when put together. The separate parts are shown in fig. 2.These are the rule L and the roller frame R, which are coupled… … B :o 3o *i *• ** *u w w» * li5 ,M w°t.l5*il- /;o 11; is; i?= w> w «J_«f. »o i« *» ;,V^ Fig. 1.—Protractor for Polar Co-ordinates.
