Manganese steel medallion made by Sir Robert Hadfield (1858-1940). Hadfield was a British metallurgist who developed manganese steel in 1882, an alloy which was particularly durable and was subsequently used in the construction of railway rails. The First World War saw an increase in demand for the steel for the manufacture of armour plating and soldier's helmets. By 1919, Hadfield's Steel Foundry was the biggest employer in Sheffield. The medallion bears a portrait of Benjamin Disraeli, first Earl of Beaconsfield (1804-1881), statesman and British Prime Minister in 1868 and 1874-1880.
© Science Museum / Science & Society Picture Library