Metrology
From the late 19th century to the middle of the 20th century Sheffield was a centre of excellence in the design, development and manufacture of precision measuring tools. In this context precision implies being able to measure accurately to at least one thousandth of an inch. The three Sheffield companies of James Chesterman, Moore and Wright and Shardlow were of major importance, especially during WW1 and WW2 when Britain urgently needed to manufacture high precision products for the war effort. Products of this kind included parts for aircraft engines and state of the art armaments which had to be made accurately to specific tolerances for interchangeable manufacturing purposes.
The collection houses a comprehensive range of measuring tools made by these three companies. Included in the collection are over 300 different designs of micrometers and an impressive range of Vernier caliper gauges and height gauges. Some of the equipment used in the manufacture of these tools is also on display including an SIP linear dividing engine, used by James Chesterman to make precision Vernier scales, slip gauges, surface plates and go/no-go gauges. Over the years many innovative products have been collected including a Moore and Wright Braille micrometer and a Braille caliper gauge which was a joint venture between Moore and Wright and James Chesterman. These are supported by engineering drawings and patent information. They were used by service people who had been blinded in WW2 and who wished to return to their peace time jobs as quality inspectors. It is highly likely that these products would have been commissioned by the RNIB. Also on display is a range of height gauges, designed by the brilliant engineer Tom Bailey of James Chesterman, with specially sectioned columns that can measure heights up to 48 inches to an accuracy of one thousandth of an inch without any appreciable deflection taking place.
Also in the collection are a number of bench measuring machines, including a very early example of an Armstrong Whitworth machine. One of the very early 3D measuring machines made by Mitutoyo of Japan is also on display.
There are also precision linear and circular slide rules which would be used by engineers in order to design many of the products in the collection. Remember these were the days before electronic calculators or computers which are now used extensively in the design and manufacture process.
Finally, the collection includes many foreign precision measuring tools so that comparisons can be made with British designs, mainly for research purposes.
David Eaton