The Building Site
Derbyshire - Detail and Character
Doors and Windows (page 67)
The sash window was made possible through an improvement in glass manufacture, which allowed larger panes to be cut from blown discs or cylinders. Spun crown glass or cylinder glass gives a window a wonderful sparkle and liveliness, as can be seen in these 'Yorkshire' sash windows in Melbourne (above) and Whitwell (left).
The Yorkshire sash is a regional variation, with the sliding part moving horizontally on a runner, rather than vertically on weighted cords. It is more common in North Derbyshire and was never used for houses with architectural pretentions.
The process of replacing old-fashioned casement windows, which had small panes of diamond-shaped or rectangular glass held together with lead cames, with larger-paned sash windows, continued into the 20th century, as photographs taken in the early 1900s reveal.
