Hamilton 'Pulsar' digital wristwatch, 1970.
© Science Museum / Science & Society Picture Library
This was the first electronic digital watch, and also the first without any moving parts. Designed in the United States by the Hamilton Watch Company of Lancaster, Pennsylvania and Electro-Data Inc of Garland, Texas, it went into large-scale production in 1972. The watch is quartz-controlled, but has a light-emitting diode (LED) digital display. To conserve battery power, the display is switched on by presing a button, switching off after a few seconds. LED watches were popular for a time, but were eclipsed by the LCD (light crystal display) watches, also introduced in 1972.