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 287
cubic whose equation in polar co-ordinates is of the form r—a sec 6—b cos 6. But this is the inverse of a conic with respect to its vertex. Hence, byadding a second Peaucellier cell to invert the curve described by P, we canobtain a conic. If the conic to be described is a parabola, the curve… … Group of Conographs exhibited by D. Gibb, M.A.Fig. i.—Ellipsograph of Prochis. Fig. 6.—Cunynghames Conograph. Fig. 2.—Barocius Conograph. Fig. 7 Fig. 3.—Schemers „ Fig. 8 Fig. 4.—Bramers ,, Fig. 9 Fig. 5.—Rottsiepers „ Fig. 10 Jiirges MaclaurinsBurstows—Guests INSTRUMENTS OF CALCULATION 259 X. The…