SET-OFFS. A set-off is nothing more than a double bend, as shown at Fig. 47, and made in much the same manner. D is the long end of the pipe. Always make this bend first and pull it up quite square, as it will be found to go a little back when pulling up the other bend; if you can make the two together so much the better, as you can then work the stuff from the throat of one bend into the back of the other. The different shaped dummies are also here shown: F a round-nosed dummy, G a double bent dummy, H a single bent, I straight, J hand-dummy, ABN a long bent dummy shown at Fig. 38. [Illustration: FIG. 47.] BAD BENDS. These can always be detected by examining them in their backs, as at Fig. 48; take a small dresser and tap the pipe a few times round ABD to test for the thickness. Strike it hard enough to just dent it; next strike the back part of the pipe, E, _with the same force_, and if it dents much more it is not an equally-made bend. I have seen some of these much-praised London-made bends that could be easily squeezed together by the pressure of the thumb and finger. N.B.--Care must be taken not to reduce or enlarge the size of the bore at the bend. [Illustration: FIG. 48.] BAD FALLS IN BENDS. The fall given in bending lead pipes should be considered of quite as much importance as making the bends of equal thickness especially for pipes, as shown in Fig. 49. In this Fig. you have a drawing of a bad bend. From A to B there is no fall whatever, as also from B to C; such bending is frequently done and fixed in and about London, which is not only more work for the plumber, but next to useless for soil-pipes. Fig. 50 shows how this bend should be made with a good fall from A to J, also from M to N; the method of making these bends requires no further explanation. R, P, and K are the turnpins for opening the ends, the method of which will be explained in a future paragraph on "Preparing for Fixing." [Illustration: FIG. 49.] [Illustration: FIG. 50.] BENDS MADE INTO TRAPS OR RETARDERS. It will sometimes be found requisite to retard the flow of water when running through soil or other pipes, or to direct it to another course, or even to form a trap in the length of pipe. This has been done in many ways, but Figs. 51 and 52 represent the method that I, after mature consideration, think most preferable. There is nothing new about this style of bending, as it has been long in vogue with provincial plumbers, but more especially in Kent. For many years it has had a run as a sink and slop closet-trap. Mr. Baldwin Latham, in his "Sanitary Engineering," says it was introduced and has been used for the Surrey and Kent sewers from about 1848. [Illustration: FIG. 51.] [Illustration: FIG. 52.]