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68 the developed miter line, and thence to the correspondingly numbered line of the stretchout. This intersection is marked with a small circle. In like manner all the remaining points in the profile of Fig. 97 should be traced and the intersections of each with its corresponding measuring line in the stretchout determined. A curve traced through these intersections will give the miter cut of the pattern.

Opening in Main Pipe.—A line of stretchout, Fig. 98, is first drawn at right angles to the main pipe. The spacings of the apparent miter line, Fig. 97, are set off upon this line, and these divisions lettered to correspond to the lettering of the apparent miter line. Measuring lines from each point are drawn at right angles to the fine of stretchout. The intersections of the developed miter line, as shown in Fig. 97, should now be lettered. It should be noticed that the position of the lettering is changed as was the numbering of the profile, and for the same reason. A line is dropped from point E of the developed miter line until it intersects line E of the stretchout in Fig. 99. The intersection is marked with a small circle. In like manner intersections for all other points of the developed miter line should be located. A curve drawn through these intersections will give the true shape of the opening in the main pipe, Fig. 99.