Picture 'postcard' ' Recollections of the Masquerade' printed on thin aluminium sheet, c.1900 Buffalo Aluminium Company, New York, U.S.A.

In the early 1890s when Hall and Heroult had only recently invented the electrolytic process for extracting aluminium, the metal was still an expensive curiosity. Although light and corrosion resistant and a good conductor, it lacked strength and stiffness. It was not until 1906 when a German metallurgist named Alfred Wilm discovered a heat treatment process, called age hardening, for certain aluminium alloys, that demand for aluminium became wide spread. This discovery revolutionized the aircraft industry for example, as now a modern aerospace material was available.