From the water supply, the cold-water pipes may be traced in the drawing directly to each of the fixtures of the house. The hot-water pipe leaves the range boiler at the top and connects with each fixture using hot water, thus making the circuit complete. Details of the piping which provides hot water is described under range boiler, page 116. [Illustration: FIG 65.--Stop and drain cock with lever handle.] [Illustration: FIG. 66.--Stop and drain cock with =T= handle.] WATER COCKS The development of modern plumbing has brought about the use of a great number of household mechanical appliances, that have received trade names little understood by the average person. The lack of distinguishing terms, or language in which to describe plumbing fixtures, often leads to embarrassment, when such articles are to be described to workmen. Common household valves and cocks are so classified by the trade, that mistakes are often made in their designation, because of a limited knowledge of the use of the various articles. A little consideration of the different classes of fixtures will make it possible to state to a tradesman the exact article in question. The term _valve_ is intended to define an appliance that is used to permit, or prevent, the passage of a liquid through the opening or port which it guards. The term is so general in its application that there are hundreds of different kinds of valves. Even for a single purpose there are many styles of a given kind. A _cock_ was originally a rotary valve or spigot used for drawing water. Today there are many kinds of cocks that are not rotary in their movement. It would be impossible in this work to describe in detail all of the kinds of cocks and valves used in household plumbing. It will, therefore, be the aim to confine attention to one article of a type and to choose such examples as are in general use and that are good representatives of their classes. [Illustration: FIG. 66_a_.--Kitchen sink with Fuller bibb-cocks.] =Bibb-cocks.=--On the kitchen sink, the water faucets, such as those shown in Fig. 66_a_, are termed bibb-cocks by the plumber. If the nozzle is plain, it is a _plain bibb_. If the nozzle is threaded so that a hose connection may be attached as in Fig. 67, it is a _hose bibb_. Bibb-cocks are found in three general styles: compression bibbs, ground-key bibbs, and Fuller bibbs. The compression bibb takes its name from the method of closing the valve. Fig. 68 gives an example of its mechanical construction. This is a plain _solder bibb_ because the shank _A_ is to be attached by a solder joint. If the part _A_ contained a thread to make a screw joint, such as Fig. 67, it would be a plain, compression, _screw bibb_. Fig. 68 is another style of compression bibb-cock, largely used on sinks; this cock, being finished with a flange, is a _compression flange bibb_. [Illustration: FIG. 67.--Compression hose bibb.] [Illustration: FIG. 68.--Compression flange bibb.]