1. Gray , Andrew , ed. 1893.Absolute Measurements in Electricity and MagnetismVol. ii, 47–47. part ieq. (81) and (82).
2. For eq. (5) seeAbsolute MeasurementsGray A. 1893 ii 245 245 part i.eq. (1), and ed. of 1921, p. 210, eq. (1).
3. Equations (13) and (14) are equivalent to equations (9) and (10),Absolute Measurements212 212 ed. of 1921, changing 1680x4to 1680a2x4