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 237
ct on the reading. Hence, if the tracingpoint be guided round such an area that the recording wheel is always movingparallel to its axis, there will be no reading. This is the case when the poleO is at the centre of the circle, whose diameter is such that the plane con-taining the edge of the… … Fig. 3. With the ordinary polar planimeter there is a possible source of error,due to the axis of the recording wheel not being parallel to the tracer arm.In order to eliminate this error, if present, it is necessary to take the mean
