Electric battery-powered Swan safety lamps, British, early 20th century.

Clanny safety lamp, 1869-1874.

Two 'bonneted' clanny lamps and two clanny lamps, c 1880s.

Two Clanny safety lamps, 1869-1874, and 'bonnetted' Clanny lamp, c 1882.

A 'bonnetted' Clanny lamp, no 19, c 1882.

Swan's electric filament lamp, 1878-1879.

Safety lamps, early 19th century.

Davy's potash experiment, c 1808.

Nernst lamp, c 1900.

Electric lighthouse lamps, 1949.

Stephenson's and Davy's safety lamps, c 1815.

Clanny's first safety lamp for mines, c 1813.