Figure 45, is denominated bead, but, and square, or more fully, bead end hut front, and square bark. In bead and but work, the bead is always struck on the outer of the panel, in the direction of the grain.
Figure 46, is denominated bead and flush front and quirked ogee, raised panel, with ovolo on the rising, grooved on fiat of panel, on back. Bead and flush, and bead and but work, are always used where strength is required. The mouldings on the inside are made to correspond with the other passage or hall doors.
Figure 47, is a collection or series of mouldings, the same on both sides, and project in part without the framing on each side. The mouldings are laid in after the door is framed square and put together. if bradded through the sides of the quirks, the heads will be entirely concealed; but observe, that the position of the brads must not be directed towards the panels, but into the solid of the framing. The mouldings of doors which thus project are termed belection mouldings ; bclection-moulded work is chiefly employed in superior buildings.
Geometrical Descriptions in Joinery.
To find the true bevel for hanging any door.
Figure 4S.—Let a be the centre of the hinge; on a b the width of the door, describe a semicircle, b c e d a, cutting the other side of the door at c and d. Join a d and b c, which will be the proper edges of the door, in order to make it open freely.
Note.—The bevelling on the side a d is of no other conse quence than to make the sides uniform.
To find the joint for a pair of folding doors.
Figure 49.—Let h and g be the centre of each hinge ; bisect h g by a perpendicular, a b, cutting the thickness of the door at a and b; bisect a b by the perpendicular c d at e; make e c and e d each equal to half the thickness that you intend the rebate to be. Suppose you intended the flap, gacdf, to open, draw a line from d to the centre of the hinge at g ; on d g describe a semicircle d f i g, cutting the other side of the door at f; join f d, and through c draw c k parallel to d f; then k c df will be the proper joint.
Note.—lf you put a bead at the joint, it ought to be equally on each side of the points a and b.
To find the bevel on the edge of a door, when it is executed on a circular plan, and the door to turn towards the space on the convex side of the circle.
Figure 50.—With regard to the circular door, all that is required is to make the angle a b c either a right angle or greater than a right angle (for a right angle is the least that any door will admit of) formed by the edge of the door, and a line drawn from the centre of the hinge to the opposite angle. • For the folding-doors.
Figure 51.—Let a and b be the centres of the hinges; join a 6, and bisect it by the perpendicular c f e, cutting the door in c and e; bisect c e by the perpendicular, g f h; make f h and f g each equal to half the thickness of the rebate : join h b; on it describe the semicircle h i k b, cutting the concave side of the door, i; join i h; through g draw g l parallel to it ; then will l g hi be the joint required.
To find the meeting joint of folding doors when the hinges are placed on the concave side of the doors.
Figure 52.—Let a and b be the centre of the hinges; join a b, and bisect it by a perpendicular, c d c, at c, cutting the thickness of the door at d and e; bisect d e by a perpen dicular, g f ir, cutting de at f; make fit and fg each equal to half the thickness of the rebate; join b h; on it describe a semicircle, h i k b, cutting the other side of the door contrary to the hinge at i; join i h, and through g draw g l parallel to h, cutting the concave side of the door at ; then will i h g be the joint sought.
Demonstration.—Let the door a lghi remain in its place; now the angle b i le being a right angle, consequently the perpendicular b i will he the shortest line that can be drawn from the point b to the line i Ir ; then suppose tne half door to be turned round the hinge at b; the point i will then describe a circle, whose centre is the hinge at b; then will i be a tangent to that circle at i; therefore the angle at i will touch no other part of the edge of the other door, but at i.