Window A window is an aperture in a wall for the admission of light. The size of windows depends on the climate, the aspect, the cubature, the proportion, the destination, and the thickness of the walls of the place to be lighted : as also on the number and distribution of win dows in that place. It is not very easy, even with these data, to determine, with mathematical exactness, the necessary quantity of light; but in private houses, where beauty and proportion arc requir ed, the width of the windows depends on the height of the principal story ; other wise the apertures will be disproportion ate figures of themselves, and also to the whole facade in which they are placed.
The apertures of windows should not only be of shapely figures, and propor tioned to the building, but the piers also should, in some measure, be regulated by the breadth of the apertures ; at least, certain proportionable limits of this breadth ought to be assigned to that of the piers, so as not to offend the eye by their being too clumsy or too small, and at the same time permit a less or greater quan tity of light, for a greater or less depth of rooms. As to the size of the piers, considerable latitude may be taken ; but in general, they should not be of less' breadth than the apertures, nor more than twice that breadth. In a small building, with only three rooms and three windows in the length, the piers will necessarily be large.
In buildings with a great number of windows in the length, where there are at least three windows in one or more principal rooms; and where there are no breaks, the breadths of the piers may be from once the breadth of the window to once and a half that breadth ' • but if there are columns, pilasters, or breaks, the breadth of the pier may be from once to twice that of the apertures, according as the breadth of the pilasters or columns may require, so as to leave a proper re pose of walls upon the sides.
The sills of windows should be from three feet to three feet six inches distant from the level of the floor, forming a pa rapet for leaning upon : these limits arc the natural heights of the breasts of win dows; but it is now common, even in ordinary buildings, to make them from two feet to two feet six inches high only. In noblemen's houses the sills are frequent ly upon the same level with the floor, and sometimes rise a step or two higher. These circumstances will alter the pro portion of the windows, and make them much higher than the double square. The width of all the windows must be the same in the same facade ; but the different heights of the stories will require different heights of windows. Were it required to find the quantity of light for a room of given dimensions, it is evident that this will depend upon the area of the inlet and the cubature of the room ; therefore, supposing that an aperture containing 20 square feet is suf ficient for a room 12 feet square and 10 feet high, that is 1400 cubic feet, the quantity of light will easily he ascertain ed for a room of any other given dimen sions. Let a room be supposed 25 feet long, 20 feet broad, and 14 feet high, the cubature will be seven thousand. feet ;
then, because the cubature of rooms should be as the area of the inlets, the proportion will stand thus : 1440 : 7000: : 20 20 1440) 140000 (97 the area of the 12960 inlet required. 10400 10080 320 Or, instead of working the proposition, divide the cubature of the room by 72, thus : 72) 7000 (97 as before.
648 520 504 16 This quotient, divided into three parts, gives nearly 32 feet for each window, which is very sufficient for light ; and al! ter deducting 12 feet, the breadth of three windows, 13 feet will remain for the Four piers, which is a very good propor tion : there is also abundant room left for any kind of furnishing above the win dows.
An odd number of windows, either in the same length of front, or in the same length of principal rooms, is always to be preferred to an even number ; for, since it is necessary to have the door in the middle of the front, an even number of windows would occasion a pier to be above the opening of the door, contrary either o regularity, or to the laws of solidity ; and in rooms nothing is more gloomy .han a pier opposite the centre of the door. Windows placed in blank arcades ilmuld have the under sides of their lin tels in the same horizontal plane with the springing of the arch ; or if the windows have a cornice, the springing of the arch ought to be carried as high as the top of theocornice.
The aperture of the windows may be from two-fifths to three-fourths of the breadth of the arcade. In the principal floor, the windows are generally orna mented; the most simple kind of which is, that with an architrave, surrounding the jambs and lintels of the aperture, and crowned with a frize and cornice. In cases where the aperture is high, in order to make the dressing of a good composi tion, the sides of the architrave are fre quently flanked with pilasters or consoles, or with both ; and sometimes with co lumns, when there is a set-off or proper base, so as not to have a false bearing. When the principal rooms are in the one pair of stairs; the windows of the round floor are sometimes left entirely plain, and at other times they are surrounded with an architrave ; or the rusticated base ment, where there is one, terminates up on their margins without any other finish. The windows in the third story are fre quently plain, and sometimes surrounded with an architrave. When the windows in the principal story have pediments, the windows of the story immediately above have !frequently their surrounding archi traves crowned with a frize and cornice. The sills of all the windows in the same floor should be upon the same level. The sills of the windows in the ground story should be elevated 5 or 6 feet at the least above the pavement in the exterior of every building the same kind of finish or character should be preserved through out the same story. Mixtures of win dows should be avoided as much as pos sible ; or, where there is a necessity for introdu cing Venetian windows,they ought to stand by themselves as in breaks.