In the development of the patterns for tee-piece in which the branch pipe is smaller than the main (Fig. 10), the method pursued is the same as with Fig. 8. It will be observed that this pattern is also formed of four equal curves, and consequently in large work the setting-out of one-quarter of the pattern will be sufficient for practical purposes. In marking out the hole the lengths 0 1, etc., are taken from the corresponding lengths around the main pipe, and the widths at the same points from the quarter-circle on branch pipe. A test as to the accuracy of working can be applied when it is remembered that the girth around the hole should be the same as the length of curve on pattern.