Making gun barrels using the Armstrong method, Shanghai, 1883.

Plate taken from the 'Illustrated London News'. William Armstrong, Baron Armstrong of Cragside (1810-1900) established a hydraulic machinery factory in Elswick in 1847. During the Crimean war, he designed a rifled, breech-loaded gun, for which he was appointed Engineer of Rifled Ordinance to the War Department. At his factory at Elswick he implemented a method of making gun barrels in which several wrought-iron cylinders were shrunk onto a steel core. These cylinders were constructed by coils of red-hot iron wound around, then welded to the core by blows from the steam hammer shown here.