In the upper part of Fig. 408 is shown the transverse section of a skylight in which A B represents a portion of the ventilator or finish at the top, and C D the curb or finish at the bottom. The section also shows the side elevation of a "common" bar whose profile is at F. The plan immediately below shows a corner of the skylight with one of the hip liars, H K, the patterns for which are required. It will be necessary first to see that the plan is correctly projected from the elevation, and afterward that a diagonal elevation of the hip bar be obtained from this plan, before the correct or raked profile of the hip bar can be obtained.

' Draw, a duplicate of normal profile F with its center line on the center line of the hip, as shown at F'.

As a means of obtaining the lateral projection of all its points, numbering corresponding points in both profiles the same. Number the intersections of all the points in the normal profile F with the top and bottom of the skylight finish, as shown by the small figures in A B and C G. From each of the points in the profile F carry lines parallel to the center line of the hip in either direction, intersecting lines of corresponding number dropped vertically from-both the miters of the transverse section to the plan. Lines traced through these points of intersection will give the miter lines at top and bottom as they appear in plan.

At right angles to the lines of the. hip carry lines, as shown, by means of which to construct the diagonal elevation. Assume any line, as E1 G1, as the base or horizontal line of the diagonal elevation representing E G of the section. At E1 erect a perpendicular upon which to obtain the rights of the various points in the upper miter. As the hip bar is required to miter with the horizontal molding at the top whose profile is shown at A B, it will be found most convenient to carry all the points of the upper profile to the vertical line A B, as shown by 1, 2, 3', 4, 5 and 6, and afterward to transfer them, as shown, to the line A1 B1, keeping the perpendicular hight from E1 to Bv1 equal to E B. From all the points in A1 B1 carry lines horizontally - that is, parallel to E1 G1 - to the right indefinitely, as shown. These lines will then represent a partial elevation of the top molding A B in the diagonal elevation. Lines from each of the points in the plan of the upper miter at H may now be carried parallel to H E' until they intersect with lines of corresponding number drawn from A1 B1. Lines connecting the points of intersection will give the required miter line at the top of the hip bar.

Fig. 408.   Plan and Section of a Skylight and Patterns for the Hip Bar. .

Fig. 408. - Plan and Section of a Skylight and Patterns for the Hip Bar. .

From each of the points obtained in this miter line carry lines parallel to B1 G1, or the rake of the hip bar, and intersect them with lines projected parallel to H E' from the lower miter in plan at K. Lines connecting these points of intersection will give the required miter line at the bottom of the hip bar.

It now remains only to obtain the correct profile of the hip bar before a stretchout can be obtained. To accomplish this, draw any line cutting the lines of the hip bar in the diagonal elevation at right angles,*as shown at R. Upon this line, and above or below the hip bar, as shown at F2, draw a duplicate of the normal profile F, from the points in which carry lines at right angles to the hip bar, cutting lines of corresponding number in the same. Then lines connecting the points of intersection will give the raked profile, as shown at R.

On account of limited space the important details in Fig. 408 are necessarily small, but great care has been taken in the preparation of the drawing, and all the points in the several views of both miters have been carefully numbered, so that the reader will have no difficulty in following out the various intersections from start to finish. The profile and the two miter lines now being in readiness, the pattern may be developed in the usual manner, as follows: Upon any line drawn at right angles to the hip bar, as L M, lay off a stretchout of the profile R, as shown by the small figures, through which draw the measuring lines. Keeping the blade of the T-square parallel with L M, bring it successively against the points of intersection previously obtained in the upper and lower miters and cut corresponding measuring lines. Then lines traced through the various points of intersection, as shown by N 0 and P Q, will constitute the required patterns.

It may be noticed that while most of the points from the normal profile F come squarely against the inner beveled surface of the curb G, the points 1 and 2, representing the vertical portion of the bar, pass over the curb to a point beyond. The line from point 2, therefore, intersects at both 2 and 21, which points are duly carried through the views of this miter at K and G1 and finally into the pattern, as shown; from which it may be seen that the miter pattern may be cut as shown by the solid line from P to Q, or that portion from point 2 to 3 may be' cut as shown by the dotted line.