Ultraquartz "Cybernetic" quartz analogue wristwatch by Longines, Switzerland, c.1969. With seconds hand and date indicator. An example of the first quartz wristwatch of European origin. Case back marked '16' and '228794'.

An ultraquartz "Cybernetic" quartz analogue wristwatch by Longines, Switzerland, c. 1969, with seconds hand and date indicator. An example of the first quartz wristwatch of European origin. Case back marked '16' and '228794'.

The frequency of the quartz crystal is not divided down electronically but is used to control and correct the vibrations of an arm by means of a cybernetic circuit. The arm vibrates at 170 cycles per second and drives the hands through a pawl and ratchet mechanism. Discrete components are used instead of integrated circuits.