0.8 cm. below the center of buoyancy. The Florentia gyro-compass is slightly pendulous.
The gyro of the sensitive element is the rotor of a three-phase motor. One of the three phases is led to the motor through the supporting spindle. The other two are led through two flexible platinum strips that extend from the phantom to the gyro-casing.
149. The Follow-Up System. - The upper end of a vertical helical spring is suspended from the upper plate of the sensitive element. On the lower end of the spring is a pair of silver balls, Fig. 198. These balls hang between a pair of vertical metal plates X, X', Fig. 199, mounted on a frame carried by the phantom element.
When the north-south line of the compass card is in the vertical