1) 5,539 3,339 Siemens (Small, No. 2) 6,864 4,138 Two Holmes's coupled 2,811 2,811 Two Gramme's (Nos. 1 and 4; but 5 can be varied by shifting the wheel to the power-agent used. ELECTRIC SIGNALLING. Fig. 102 represents the normal action of light bodies to which the.