little used, and are apt to admit draughts and wet unless efficient checks are worked upon the sashes and frames.
Fig. 8.—Casement window fitted with shutters.
Lights in a position difficult of access are often hung on centre pivots. An example of this method is shown in fig. 8; metal pivots are fixed to the frame and the sockets in which these pivots work are screwed to the sash. Movement is effected by means of a cord fixed so that a slight pull opens or closes the window to the desired extent, and the cord is then held by being tied to, or twisted round, a small metal button or clip, or a geared fanlight opener may be used. For the side sashes of lantern lights and for stables and factories this form of window is in general use.
Fig. 9.—Details of French Casement to open inwards.
In the British Isles and in America the most usual form of window is the cased frame with double hung sliding sashes. This style has many advantages. It is efficient in excluding wet and draughts, ventilation may be easily regulated and the sashes can be lowered and raised with ease without interference with any blinds, curtains or other fittings, that may be applied to the windows. In the ordinary window of this style, however, difficulty is experienced in cleaning the external glass without assuming a dangerous position on the sill, but there are many excellent inventions now on the market which obviate this difficulty by allowing—usually on the removal of a small thumb-screw—the reversal of the sash on a pivot or hinge. For a small extra cost these arrangements may be provided; they will be greatly appreciated by those who clean the windows. The cased frames are in the form of boxes to enclose the iron or lead weights which balance the sashes (fig. 7), and consist of a pulley style—which takes the wear of the sashes and is often of hard wood on this account—an inside lining, and an outside lining; these three members are continued to form the head of the frame. The sashes are connected with the weights by flax lines working over metal pulleys fixed in the pulley styles. For heavy sashes with plate glass, chains are sometimes used instead of lines. Access to the weights for the purpose of fitting new cords is obtained by removing the pocket piece. A thin back lining is provided to the sides only and is not required in the head. The sill is of oak weathered to throw off the water. A parting bead separates the sashes, and the inside bead keeps them in position. A parting slip hung from the head inside the cased frame separates the balancing weights and ensures their smooth working. The inside lining is usually grooved to take the elbow and soffit linings, and the window board is fitted into a groove formed in the sill. The example shown in fig. 7 has an extra deep bottom rail and bead; this enables the lower sash to be raised so as to permit of ventilation between the meeting rails without causing a draught at the bottom of the sash. This is a considerable improvement upon the ordinary form, and the cost of constructing the sashes in this manner is scarcely greater.
Bay windows with cased frames and double hung sashes often require the exercise of considerable ingenuity in their construction in order that the mullions shall be so small as not to intercept more light than necessary; at the same time the sashes must work easily and the whole framing be stable and strong. The sills should be mitred and tongued at the angles and secured by a hand-rail bolt. Frequently it is not desired to hang all the sashes of a bay window, the side lights being fixed. To enable smaller angle mullions to be obtained, the cords of the front windows may be taken by means of pulleys over the heads of the side lights and attached to counter-balance weights working in casings at the junction of the window with the wall. This enables solid angle mullions to be employed. If all the lights are required to be hung the difficulty may be surmounted by hanging two sashes to one weight. Lead weights take up less space than iron, and are used for heavy sashes.
In framing and fixing skylights and lantern lights also great care is necessary to ensure the result being capable of resisting rough weather and standing firm in high winds. Glue should not be used in any of the joints, as it would attract moisture from the atmosphere and set up decay. Provision must be made for the escape of the water which condenses on and runs down the under side of the glass, by means of a lead-lined channelled moulding, provided with zinc or copper pipe outlets. The skylight stands on a curb raised at least 6 in. to allow of the exclusion of rain by proper flashing. The sashes of the lantern usually take the form of fixed or hung casements fitted to solid mullions and angle posts which are framed into and support a solid head. The glazed framing of the roof is made up of moulded sash bars framed to hips and ridges of stronger section, these rest on the head, projecting well beyond it in order to throw off the water.
Shutters for domestic windows have practically fallen into disuse, but a reference to the different forms they may take is perhaps necessary. They may be divided into two classes—those fixed to the outside of the window and those fixed inside. They may be battened, panelled or formed with louvres, the latter form admitting air and a little light. External shutters are generally hung by means of hinges to the frame of the window: when the window is set in a reveal these hinges are necessarily of special shape, being of large projection to enable the shutters to fold back against the face of the wall. Internally fixed shutters may be hinged or may slide either vertically or horizontally. Hinged folding boxed shutters are shown in the illustration of a casement window (fig. 8), where the method of working is clearly indicated; they are usually held in position by means of a hinged iron bar secured with a special catch. Lifting shutters are usually fitted in a casing formed in the window back, and the window board is hinged to lift up, to allow the shutters to be raised by means of rings fixed in their upper edges. The shutters are balanced by weights enclosed with casings in the manner described for double hung sashes. The panels are of course filled in with wood and not glazed. The shutters are fixed by means of a thumb-screw through the meeting rails, the lower sash being supported on the window board which is closed down when the sashes have been lifted out. Shutters sliding horizontally are also used in some cases, but they are not so convenient as the forms described above.
Shop-fronts.—The forming of shop-fronts may almost be considered a separate branch of joiner’s work. The design and construction are attended by many minor difficulties, and, the requirements greatly varying with almost every trade, careful study and close attention to detail are necessary. In the erection of shop-fronts, in order to allow the maximum width of glass with the minimum amount of obstruction, many special sections of sash bars and stanchions are used, the former often being reinforced by cast iron or steel of suitable form. For these reasons the construction of shop-fronts and fittings has been specialized by makers having a knowledge of the requirements of different trades and with facilities for making the special wood and metal fittings and casings necessary. Fig. 10 shows an example of a simple shop-front in Spanish mahogany with rolling shutters and spring roller blind; it indicates the typical construction of a front, and reference to it will inform the reader on many points which need no further description. The London Building Act. 1894 requires the following regulations to be complied with in shop-fronts:—(1) In streets of a width not greater than 30 ft. a shop-front may project 5 in. beyond the external wall of the building to which it belongs, and the cornice may project 13 in. (2) In streets of a width greater than 30 ft., the projections of the shop-front may be 10 in. and of the cornice 18 in. beyond the building line. No woodwork of any shop-front shall be fixed higher than 25 ft. above the level of the public pavement. No woodwork shall be fixed nearer than 4 in. to the centre of the party wall. The pier of brick or stone must project at least an inch in front of the woodwork. These by-laws will be made clear on reference to fig. 10, which is of a shop-front designed to face on to a road more than 30 ft. wide.
Rolling shutters for shop-fronts are made by a number of firms, and are usually the subject of a separate estimate, being fixed by the makers themselves. The shutter consists of a number of narrow strips of wood, connected with each other by steel bands hinged at every joint, or it may be formed in iron or steel. This construction allows it to be coiled upon a cylinder containing a strong spring and usually fixed on strong brackets behind the fascia. The shutter
