From the latter experiments and their modifications, it became evident that the magnitude and shape of the Od-subject have each a direct influence on the result. A greater force of attraction evidently exists towards the greater mass.
XIV. Odometer held over the northward pole of a magnetic needle contained in a compass-box under glass. Result—Rotatory motion in the direction of the hands of a watch.
XV. Odometer held over the southward pole. Result—Rotatory motion in the direction contrary to the motion of the hands of a watch.
XVI. Repeat experiments XIV. and XV., with the difference of touching the forefinger implicated in the odometer with the thumb of the same hand. Results—The rotatory motions observed in the two experiments referred to become exactly reversed.
XVII. Hold the odometer over the centre of the needle. Result—Oscillations at right angles, or transverse, to the axis of the needle.
XVIII. Hold the odometer over, and half an inch to one side of, the centre of the needle. Result—Oscillations parallel to the axis of the needle.
XIX. Repeat experiment XIV. Then, during its continuance, place a pile of three sovereigns on the compass-box, in front of the northward pole of the needle, and about an inch from it. Result—Direction of original rotatory motion reversed.
Then follow experiments with results exactly parallel to the preceding, having the greatest physiological interest.
XX. Hold the odometer over the tip of the forefinger of your disengaged hand. Result—Rotatory motion in the direction of the hands of a watch.
XXI. Hold the odometer over the thumb of your disengaged hand. Result—Rotatory motion against that of the hands of a watch.