Cosor portable oscilloscope, c 1952.

'East View of Ely from the Railway', 1845.

Electroencephalography (EEG) cap, 1999.

Crookes' mill-wheel tube, 1879-1888.

Electrode.

Electric iron, c 1880.

Early electric iron, c 1880.

Booth's original red trolley vacuum cleaner

Colliery and wagonway, Northumberland and Durham coalfield, c 1845.

'North Eastern coalfield: colliery pit-head and coking ovens', c 1845.

Electrode with six-pronged rake end.

Graphite electrode. Light micrograph in cro