The Aperture on a facade, used for airing and premise illumination, is called as a window. Its top part is fixed by a horizontal beam-crosspiece, in certain cases - the arch with the lock. The horizontal external window sill and a vertical slope of a window aperture are generated in a rectangle. The window aperture can be divided by a rack and impostom. Vaulted crosspieces block the remained apertures and give to a window the various form.
In the past the window height considerably surpassed width that has been connected with complexity of strengthening of the top crosspiece of a window.
To warm a window, but thus to provide the maximum penetration of light into a premise, the considerable quantity of designs and adaptations has been invented. As a result of these searches by the most successful variant there was a window with the glazed mobile frame from a tree.
In 1845 start to make flat glass, and in XX century - glasses of the big sizes, using a method of exhaust hire.
With the advent of large structures of the Roman period the window form start to typify. In the Roman provinces on Rhine and Danube the greatest popularity have received simple polutsirkulnye windows ( fig. 16 ). They settled down in pairs or arcades abreast, increasing thus access of light to a premise, being during too time a magnificent architectural ornament.
a Fig. 16. Romance double polutsirkulnoe a window.
During the late Romance period there are windows with the most various forms and florid ornaments. .
In the Middle Ages of a window of apartment houses were closed by window shutters which I settle down in an internal part of a premise more often. From XIII century them glazed in the top part utolshchennymi in the middle glasses which had the round or diamond-shaped form.
At the time of a gothic style at manufacturing of windows skeletons began to be used. In this connection window apertures have increased till the huge sizes, more often it was observed at building of cathedrals, temples and churches. As a rule, they had freakish ornaments and were carried out with high art taste ( fig. 17 ). .
a Fig. 17. The late Gothic socket in the form of the fish bubbles making rotating ornament.
In the lancet crosspieces located over streloobraznymi windows, the openwork stone ornament ( fig. 18 ) prevails.
a Fig. 18. Pair windows with an ornament in the form of a square with semicircles inside and a small capital imposta in a design.
During the Renaissance epoch the most popular were polutsirkulnye or rectangular windows. They were decorated by frames with ornamental patterns, a crosspiece - sandrikami, and as a support external window sills were served by consoles. The form edikuly was given to a window by a parapet and an ornament with pilaster or column use. The form and window proportions have laid down in a basis of the theory which have arisen in this period of architecture. .
In baroque there is a big variety of forms of windows ( fig. 19 ): oval, rectangular, blocked polutsirkulnymi, segment or box-shaped arches, with freakish lattices, with a rich frame etc. .
a Fig. 19. A baroque window of arch gallery Tsvingera (1711-1728):
1 - a frieze; 2 - zamkovyj a stone; 3 - a garland; 4 - a scallop; 5 - impost; 6 - a pilaster; 7 - cross-beams of window cover; 8 - a field podokonnogo a parapet; 9 - socle eaves; 10 - the console with a bearing sculpture; 11 - base a pilaster; 12 - the console with a mask and leaves akanta
In window classicism did not differ splendour of decorative registration. The modernist style has brought the big variety of new forms which were used throughout all XX century in architecture, getting modern decorative elements and continuing to serve as the most important components of an ornament of a facade of a building. .
The Glazed modular facades in modern structures have appeared thanks to steel and ferro-concrete skeletons of buildings, modular elements for structurally not intense external walls, to new ways of ventilation and heating of premises.