Prior to automatic systems, the subscriber rang an operator who would quote the time from a central clock in the exchange with a phrase such as "The time by the exchange clock is...". This was not precise and the operator could not always answer when the subscriber wanted. In 1954, British-made systems were installed in Melbourne (1st floor, City West Exchange) and Sydney. The mechanical speaking clock used rotating glass discs where different parts of the time were recorded on the disc. A synchronous motor drove the disc with the driving source derived from a 5 MHz quartz oscillator via a multi stage valve divider. This was amplified to give sufficient impetus to drive the motor. Because of the low torque available, a hand wheel was used to spin the motor on start up. The voice was provided by Gordon Gow. The units were designed for continuous operation. Both units in Melbourne and Sydney were run in tandem (primary and backup). For daylight saving time changes, one would be on line while the second was advanced or delayed by one hour and at the 02:00:00 Australian Eastern Standard time, would be switched over to the standby unit.