Synchronous mains electric clock of the non self-starting type, c 1936.

Flour calculating slide rule, c 1910.

Lighthouse optic from Eilean Glas lighthouse, 1907.

Electric master clock of the half minute impulse type in mahogany case, c 1931.

Horizontal magnetic sundial, German, c 1800.

Detail of Vulliamy's regulator clock, c 1780.

Self-reproducing mechanism models, 1920-1970.

TIM calculating machine, c 1916.

Ivory diptych sundial, 1651-1700.

Self-reproducing mechanism models, 1920-1970.

Cristalonic solar-quartz time computer, c 1970s.

Sony Ericsson T610 mobile 'phone, 2003.