Telephone Operators at a switch-board in Viborg.

 

The clock was made for the exchanges of the Danish telephone companies during the period 1945-1978. The clock was used to monitor how long time a subscriber was calling long-dis-tance.

When the telephone operator connected a call, she started the clock. After 3 minutes the clock rang, and the telephone oper-ator interrupted the conversation saying: "Three minutes. Do you wish to continue?" Then the subscriber could choose to either end his conversation or ask for another period of 3 min-utes.

How to use the Clock

Pull up the small arm on the right to start the clock. After 3 min-utes the clock will ring. To stop the clock, bring down the arm and the time spent can be read. To continue the clock, pull the arm up again and the measurement of time will proceed. To reset the clock, pull down the arm until the hand is back in place. The clock can be used as a unique egg-timer. Soft-boiled: 3 minutes, hard-boiled: 6 minutes 

The Master Clock as it appeared at the exchange.  

Details

The Junghans master clock is available in two versions:
Master Clock, up to 6 minutes, diameter 93 mm. The clock has a flat back and can be mounted on a wall.
Master Clock, up to 3 minutes, diameter 58 mm
As far as possible, the clock is delivered in its original packaging. Price: DKK 250.

The Clock's Way to the Shop

From TDC Ltd. Post & Tele Museum has received a stock of master clocks, fresh from the factory - originally a part of the stock of spare parts for the manual telephone exchanges. The museum has se-lected an adequate number for its collections, and is now selling the surplus stock in the museum shop.