Silk strength tester by Goodbrands Co of Manchester and Stalybridge

An oak cased brass pantograph by Thomas Dunn of 50 North Street, Edinburgh. Interior of case has trade label: Thomas Dunn, optician, mathematical and philosophical instrument make...

A mid twentieth century Campbell–Stokes sunshine recorder, by Casella & Co, London. Pattern: Mk III C 45- 65 (latitudes 45° – 65°, North or South). 4 inch glass sphere. Serial number: 6962 Marked: CASELLA LONDON MADE IN ENGLAND 6962 For similar Casella sunshine recorders see the collections of: Science Museum, London. OBJECT NUMBER:1995-820. The National Museum of the Royal New Zealand Navy, Torpedo Bay, New Zealand. The Campbell–Stokes sphere is used to record sunshine. It was invented by John Francis Campbell in 1853 and modified in 1879 by Sir George Gabriel Stokes. The original design by Campbell consisted of a glass sphere set into a wooden bowl with the sun burning a trace on the bowl. Stokes’s refinement was to make the housing out of metal and to have a card holder set behind the sphere. C. F. Casella and Co: Established in 1810 as Tagliabue and Casella. Incorporated as a limited liability company, C. F. Casella and Co, in 1910. Circa 1930: C. F. Casella and Co Ltd., of Regent House, Britannia Walk, London, N1 7ND - Makers of anemometers, anemographs, barometers, barographs, hygrometers, hygrographs, radiation instruments, rain gauges...

This is a large vintage pantagraph. An English, brass scientific mapping instrument, dating to the mid-20th century, circa 1950. Fascinating scale and mechanical interest Displays a...

Herschel actinometer, 1930s, wood and brass, signed Griffin & Tatlock ltd London. It is an instrument invented in 1825 by John Herschel and used for the measurement of the solar heat...