Transoms over doors or windows may be hung either at the top or bottom by common hinges, or pivoted in the centre horizontally. If the transom is to be hinged it is generally best to put the hinges at the bottom of the sash, especially over outside doors or windows, as better protection is afforded against wind and rain, and there is less trouble from draughts. It is also more trouble to enter through a transom hung at the bottom. There is an objection to hanging large transoms at the bottom, however, in that should the fixture which holds the transom open, give way, the transom will swing down against the door and very likely break the glass by the fall. Large outside transoms should therefore be centre hung (pivoted) with the bottom swinging out. It is, however, more difficult to screen a pivoted transom than one hinged at top or bottom. Transoms over inside doors are more easily operated when pivoted or hinged at the top.
For hanging the transom at top or bottom, 2 or 2½-inch "narrow-butts" (Fig. 408) are commonly used. They may also be obtained with ball tips, as in Fig. 409, but should have a fast joint.
■ When pivoted at the centre of the ends, sash centres such as are shown in Fig. 410, make as good a pivot as any for transoms of ordinary size, and the common spring window bolt, Fig. 411, also answers the purpose very well where an especially fine appearance is not necessary. There are also two or three patterns of surface sash centres. In private residences it is well to pivot inside transoms so that they can be readily removed without using a screw driver. Small pivoted transoms require only a catch at the top (one with
Fig.409a ring pull is most convenient) to fasten them when closed, as no special fixture is required to control them when open. Large transoms, and pivoted transoms over outside doors should be fitted either with a " transom lifter " or the sash adjuster, shown in Fig. 436.
Fig. 410. - Sash Centres.
Transoms hung at the bottom are sometimes provided with a transom catch, which can be opened by a cord or pole, and with chains attached to the frame or sash which permit the transom to open only a certain distance. This arrangement, however, is not very satisfactory, and it is much better to use a transom lifter of the type shown in Fig. 412. There are several transom lifts of this general type, differing from each other principally in the manner of locking or holding the rod and in the details of their joints. They may be used for transoms hung top or bottom or pivoted, and may be placed at either side of the door. About the neatest transom lifter that the author has seen, is the Yale, which has two steel grip plates which are forced against the rod by strong spiral springs and are released by turning a a neat thumb knob. A superior transom lifter is also made by the Payson Manufacturing Co. Common transom lifters are made with wrought iron rods and cast iron brackets and fittings, and are finished only with bronze paint. The better kinds, however, can be had either in bronzed steel or iron; bronze plated in various finishes on steel; Bower-Barff; or in solid bronze or brass to match any style of finish. The stock lengths are 3, 4, 5 and 6 feet, but they can be made up to 9 feet in length if so ordered. For lifters 5 feet long or over, the rod should be % inch in diameter.
Fig. 411. - Spring Window Bolt.