Self-reproducing mechanism models, 1920-1970.

Dictograph loudspeaking 'master' house-telephone unit, c 1940.

Casio LCD digital watch, 1999.

Single sand glass in five pillared wooden mount, 18th century.

Radon monitors, c 1990.

Cristalonic solar-quartz time computer, c 1970s.

Glass measuring cylinder, 19th century.

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.