WINDOWS.
Light is often limited or misapplied on account of faulty position or size of windows. The use of pilastered walls permits the introduction of larger windows, which are in most instances virtually double windows, the two pairs of sashes being set in one frame separated by a mullion. A more recent arrangement, widely adopted in English practice, is to place a swinging sash at the top of the window, which can be opened, when necessary, to assist in the ventilation, while the main sashes of the window are permanently fixed.
Rough plate glass is used in such windows, because it gives a softer and more diffused light, which is preferred to that from ordinary clear glass. White glass may be rendered translucent by a coat of white zinc and turpentine.
The top of a window should be as near the ceiling as practicable, because light entering the upper portion of a room illuminates it more evenly, and with less sharply marked shadows, than where the windows are lower down.
The walls below the windows should be sloped, in order that there may be no opportunity to use them as a resting place for material which should be placed elsewhere.