Chapter VII. Cast-iron pipes are either socketed or flanged. In (Part 5)

the elaborations of air conditioning. Natural and Artificial Lighting. To be sanitary in the fullest sense of the word, a building must not only be well warmed, it must also be well lighted, both naturally and artificially. Even in olden times this fact was recognised, for one finds the following in the writings of Lucar, who lived in Elizabeth’s time: ‘‘ For Heaven’s sake make all the rooms of youre house lightsome, of a convenient height and of a laudable largenesse. Beware you do not sleepe in a close place.” Natural Lighting. In the very earliest times of which we have details, glazed windows were unknown, the ancients providing wide, low openings to their one-storey houses, just under the eaves of the roof, high enough up in the walls to ensure privacy, the openings serving for both light and ventilation. This arrangement influenced the whole of their architecture. The ancient Egyptians used similar openings with gratings. One often finds windows referred to in the Bible, but there are seven words in the original writings which have all been translated “window”. The windows in the ark of Noah were, according to correct translation, translucent, and are believed to have been filled with an arrangement of polished oyster shells. In the Book of Judges, windows with movable lattices are definitely referred to. The use of glass for glazing windows was known to the Romans, though tale was more largely used by them, while they also used sheets of oiled linen and thin plates of horn. One reads of the Emperor Caligula neglecting the duties of state to supervise the reconstruction of his windows with sheets of glass instead of sheets of tale. The excavations at Pompeii have brought to light the fact that glass windows were used in the better houses, while the baths had windows glazed with plate glass ground or obscured on one side to prevent people seeing through. Various materials have been used for covering window openings. Thus, the Greenlander of to-day fills them with the maws of hali- buts. The Saxon used oiled linen, panels of horn, and lattices of wicker work or thinly cleft oak. The Romans, during their occu- pation, do not seem to have introduced the use of glass for this purpose in Britain, and the earliest mention of glass windows in England is in respect of the glazing of the windows of a chureh in York in 627 a.p. By the time of Chaucer (14th century) its use was more general, and in his “Dreme” he thus describes his bedroom: 148 THE BUILDING—ITS WARMING AND LIGHTING With glas Were alle the windowes well yglazed. His poems also show that the casement window was in use then. Till the time of Henry VIII, however, the use of glass did not be- come very general, and one reads, in the records of Alnwick Castle, that the glazed windows were taken out and put in a place of safety while the family were away ! Early Sash Windows. The sash window was introduced about the time of the Great Fire of London, the upper one being fixed and the lower one raisable, being kept up by a system of notches and catches. The sash window with the sashes hung by means of cords and weights, as now used, is believed to be a Dutch inven- tion, and was certainly introduced into this country with the arrival of William of Orange. Modern Natural Lighting. Present-day natural lighting is pro- vided by glazed windows, lantern lights, skylights, fanlights, roof- lights, glazed doors, and sometimes even by wall panels con- structed of glass bricks. Every habitable room should have a window opening into the external air, which is usually insisted upon irrespective of any other ventilating openings which may be provided. Factories, workshops and sometimes other buildings as well, are often pro- vided with diffused natural light by means of roof glazing on the northern slopes of the roof while the southerly slopes, which might let in too much direct sunlight for the good of the work in hand or the comfort of the workers, are clad with slates, tiles or corrugated asbestos. Local by-laws often prescribe a minimum window area, for domestic buildings, not less than one-tenth of the floor area. This figure is the minimum allowance to satisfy the by-law, and not of necessity the ideal. Most architects look upon one-seventh of the floor area as a more satisfactory allowance, but it should be remembered that large windows entail greater expense in warming the building. Placing of Windows. A further usual provision is that a minimum amount of the window area, equal to one-twentieth of the floor area, shall be made to open. Windows should be very carefully placed in designing a house. They should extend as nearly to the ceiling as possible and should be in the middle of a wall. If placed at one end of a wall, the room will not be nearly so well lighted as if the window is in the middle of the same wall. Vita Glass. Most windows are glazed with ordinary sheet glass, but for nurseries, sanatoriums, hospitals and schoolrooms, “ Vita” glass, or some similar type, made from a formula to pass as many THE BUILDING—ITS WARMING AND LIGHTING 149 as possible of the ultra-violet rays, may be worth the additional expense. Pilkingtons Double Glass. A very useful type of glass for conserving heat in the house is provided with spacing pieces at the edges providing a very narrow air-cavity and passe-partouted round the edges. It will fit into the rebates of most normal glazing bars intended for single glass. The two sheets of glass are hermetically sealed at the edges, so there is no fear of dust or vapour in the interior clouding the vision and the “U” trans- mission factor is about half of what it would be for “single” glass. School Lighting. Schools should receive special attention to their lighting, and most education authorities insist on about double the usual allowance of window area, with the light designed to fall from the side of scholar and teacher alike, and for preference from the scholar’s left, so that no shadow is thrown on the exercise book when writing. Plate and Other Types of Glass. For very large windows and first-class work plate glass must be used. Where the glass need not be transparent it is possible to get increased light by using a highly refractive glass such as muranese or prismatic. Both have a raised pattern on one side of the sheet, and this should be on the inside of the room. In the case of prismatic glass the pattern takes the form of straight V-shaped grooves over the whole surface; these should be placed horizontally in order to refract the light and divert it into the room instead of letting it fall on to the floor just inside the window. This sort of glass is often used for in- creasing the light in dark offices, but it is little used in domestic buildings, on the ground of appearance. For offices in narrow streets, outside reflectors are frequently used, but these are not very suitable for domestic work. Reflective Surfaces. If the window opens on to a small enclosed yard, or there is a wall opposite and not far from it, the light may be increased by facing the wall with white glazed tiles, or by white- washing it. White glazed surfaces, when used externally, rapidly collect dirt, and unless kept clean are no more efficient than white- wash. Wherever the latter is used it should be renewed annually, and the former should only be used where it can be readily cleaned. Where there is a basement to a house with a forecourt, the area in front of the basement windows is often too narrow. The light may be increased by sloping back the area wall, in a direction away from the window, and lining it with tiles or whitewashing it. Where there is no forecourt, areas in the front of basement windows 150 THE BUILDING—ITS WARMING AND LIGHTING are covered with gratings. These should be made up of narrow, deep bars, placed at right angles to the face of the building. If placed in a direction parallel to the face of the building, they obstruct far more light. With new buildings, the architect must acquaint himself with any local by-laws which may be in force as to the open space to be left at the back and front of domestic buildings, while the requirements of Public Health Acts, The London Building Acts (for the London area) and the Town and Country Planning Acts must be consulted. Some brief notes of these will be found in