upon the nosing; fig. 3, the raking-mouldings, found as in fig. 1, pl. XLIX. Figure 4 shows the same thing, when the mouldings are to be placed around an internal space.

58. Figure 5, plate L, represents raking-mouldings for angle-bars of shop-fronts: abcd, &c. is the given moulding. Take any number of points, a, b, c, d, &c., in the curve, and draw lines, aa', bb', cc', dd', &c., parallel to the face of the window; draw a line k'i' perpendicular to the mitre line. Then, through the points a, b, c, d, &c., draw lines perpendicular to the line of the face of the window, cutting it at the points e, f, g, h, i. Transfer the distances between the points e, f, g, h, i, to the line k'i', which is drawn perpendicular to the mitre-line, at e',ƒ'‚ g', h', i'; then draw lines parallel to the mitre-line, cutting the lines drawn parallel to the front at the points a', b', c', d', &c., and, through the points, a', b', c', d', &c., draw a curve, and it will form one side of the angle-bar: then, making the other similar, the whole angle-bar will be formed.

Figure 6 shows another design of a bar, where the window returns at an obtuse angle. The method of forming the angle-bar is the same as in fig. 5.

HINGING, AND THE FORMATION OF JOINTS.

59. A considerable degree of care is necessary to hang a door, a shutter, or any other piece of work, in the best manner. With regard to the hinge, the pin should be perfectly straight and cylindrical, and the parts accurately fitted together.

The hinges should be placed, so that their axes may be in the same straight line; as any defect, in this respect, will produce a considerable strain upon the hinges every time the door or shutter is moved, and it not only prevents it moving freely, but is also very injurious to the hinges.

60. In hanging doors, centres are often used instead of hinges; but on account of the small quantity of friction in centres when they are well made, a door moves too easily, or so that a slight draught of air accelerates it so much in falling to, that it shakes the building, and is disagreeable. We have seen this, in some degree, remedied, by placing a small spring to receive the shock of the door. The greatest difficulty, in hanging doors, is to make them to clear a carpet, and yet shut close at the bottom. To do this, that part of the floor which is under the door, when shut, may be made to rise about a quarter of an inch above the general level of the floor; which, with placing the hinges so as to cause the door to rise a little as it opens, will be sufficient, unless the carpet should be a very thick one.

Several mechanical contrivances have been used for either raising the door, or making a part to spring close to the floor, as the door shuts.

The latter is much the better method. But, by attention to rise the floor, and hinging the door properly, these contrivances are rendered of little value, while, when they are resorted to, they are seldom long in order.

61. Various kinds of hinges are in use. Sometimes they are concealed, as in the kind of joints called rule-joints; others project, and are intended to let a door fold back over projecting mouldings, 2s in pulpit-doors: when hinges project, the weight of the door acts with an increased leverage upon them, and they soon get out of order, unless they be strong and well fixed. 6%. The different objects to be attained by hinges will be best illustrated by examples.