Aluminium bulkhead for the International Space Station, USA, October 1997.

Four 'Detective Cameras', 1889-1908.

Double bur reader.

Model of an ancient Polynesiam double saili

'The Double Tricycle' and the 'The Double Action Tricycle', 1869.

Edgeley double deck electric tram.

Manchester, Middleton, Rochdale double deck electric tram.

Double-sided miner's pick, 19th century.

Double-sided miner's pick, 19th century.

Model of double beam engine, 1840.

Tindall's full size mangle, 1850.

Combined circular and spiral slide rule, in a wooden frame, 1882.