As the title American Industrial Architecture (1876-1929) suggests, Miron Mislin and Rosemarie Lazarus analyse the architecture of American factory buildings during this period, also known as the "Gilded Age". They show not only how construction methods were influenced by the technical innovations of the time, but also by contemporary tastes and economic developments. Together with mechanical and industrial engineers, the architects developed innovative planning and construction methods and tested them on new materials such as glass, iron and reinforced concrete. They provided the industrial buildings with flexible floor plans and adaptable building envelopes for the changing production conditions. The façade design initially remained committed to historicism, but a trend towards a new aesthetic design of factory buildings with significantly larger window openings and smooth façades can be observed around the turn of the century. American "Industrial Modernism" focussed primarily on the practicality (functionality) of the buildings, rather than on symbols and visual effects such as "monumentality", which were considered typical of industrial buildings in German architectural theory. The overriding principle was the effectiveness of all means used.