Even where it is comparatively strong it is largely exotic. The membership is mainly Scottish, and the ministers I Drysdale, History of the Presbyterians in England, p. 625.
A form of potentiometer employing a vibration galvanometer and suitable for alternating current measurement by null methods has been devised by Dr Drysdale (see Proc. Phys.
Hugh Drysdale, 8222; .
Drysdale, " Resistance Coils and Comparisons," British Association Report (Leicester, 1907), or the Electrician, 57, p. 955 (1907), and 60, p. 20 (1907); J.