One of a group of specimens illustrating the dressing and smelting of ores, German method - smelting of lead ore and separation of silver - silver refining - sample of silver of standard purity

One of a group of samples of rare and other metals in a pure state - antimony

One of a group of samples of rare and other metals in a pure state - selenium

One of a collection of samples of chemicals - 90 grams of Bismarck brown

One of a collection of samples of chemicals - 70 grams of Hofmann's violet

One of a collection of samples of chemicals - 100 grams of indigo

One of seven original drawings of the engine and seating supplied by Messrs Boulton and Watt to Messrs Bott, Birch, Bower and Randall - a detail of the top of the connecting rod and its connection to the working beam, February 1796

Wireless telegraph trench set transmitter, continuous wave Mark III*, No. 3470. made at the Wireless Telegraph Factory, Soho

Diagrammatic chart of electromagnetic waves, giving specifications and illustrations of use, by W.S. Kennedy Smith, late 19th - early 20th century

"A Specie Book", currency tables for use in conjunction with the Rotula Arithmetica, by George Brown, 1700

Crystal wireless receiver, type C form A made by the British Thomson-Houston Co. of Coventry, with variometer tuning, two switchable crystal detectors, a condenser, and in a polished wood box

Richards improved steam engine indicator, in wooden box. late 19th century

Orienteering compass, in clear acrylic with black-rimmed compass dial (luminous needle), magnifier and map scales on two sides, in packaging, by Silva of Sweden, c. 1985

Visual tests for colour blindness, by Dr. Shinobu Ishihara of Tokyo in 1936

Calligram of black and blue ink on buff parchment paper, original work, with design showing a bold interpretation of various Arabic calligraphic scripts treated as abstract motifs rather than as inscriptions: Tunisian, Tunis City, by Nja Mahdaoui, 1991

Colour woodblock print, depicting the courtesan Hana-ogi of Ogiya with a companion, with a poem by Yodono Sogyu: by Chōkōsai Eishō, Japan, c. 1800