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 224
e. (b) Linear, in which the guiding curve is a straight line. (c) Planimeters in which the guiding curve is not any curve in particular. (a) Polar Planimeters If another arm OB, called the polar arm, have the end O fixed at O, whichis called the pole, and the other end jointed at B, the point B is… … Fig 196 SECTION G If OB be equal to b, the general formula gives S = ;z/, or S=nl-\-2Tral-\-7rl2-{-Trb2, according as the circle is entirely outside or entirely inside the area S. If very accurate results are required, account must be taken of severalsources of error. One of these errors is that…
