CHAPTER II.
The Polar Planimeter.
Most Favorable Position.
The best position of the Polar Planimeter with relation to the outline
of the figure to be traced is shown in Fig. 3, of Plate
V. In general the “favorable” position of the Instrument with relation
to any figure may be determined by the following general rule: Place
the Tracer at the center of the figure to be measured and place the pole
P in such a position that a line drawn from the Pole P to the rim of the
Wheel W will be at right angles to the Tracer Arm. This position is
indicated by Fig. 3 of Plate V, as mentioned above.