Desirable Ends.—The general result of the varied consideration of the subject may be stated thus: That all pipes should have such fall and be so flushed as to render any accumulation of waste impossible; that leakage both of liquid and of air must be prevented; that the piping should be in full view and easily accessible for repairs and cleaning; that it should be concentrated as much as possible in one portion of the building; that sim plicity of arrang-ement is conducive to safety; and that all piping should run as directly as practicable.
of the modern suggestions is substantially as follows: That a broad recess built in the masonry of a party-wall in the line of the bath- and toilet-rooms could connect the necessary plumbing with the smoke-flue of the furnace, the heat from which would promote circulation in a ventilation-pipe. The recess, enclosed in masonry-, with brick platforms on the line of the floors, made tight around the pipes with cement, would protect the woodwork from overheating, while all parts of the plumbing, could be left readily- accessible. The soil-pipe should be supported upon the foundation wall or upon a pier, and the junction with the drain-pipe be made with an easy bend, to prevent the accumulation of obstructive matter and to lessen the back-pressure of air upon the traps. The main drain should run in full view upon the foundation wall or in a trench of concrete, with a fall of Y., an inch to the foot when practicable. It should be trapped just inside the cellar wall when possible, or otherwise in a man hole outside. A water-conductor run into this trap would insure its flush ing. A fresh-air inlet just inside this main trap provides a complete cir culation through the soil- and drain-pipes. To assist the free flow, all angles and bends in piping should be as smooth and gradual as possible. Circular apertures assist the discharge, offering- less obstructive surface in proportion to the area; and small orifices, from friction, discharge less under the same pressure than those larger and of the same shape. The discharge of a cylindrical horizontal tube can be increased by extending it to a leng-th four times the diameter of its orifice. Wrought-iron pipes suited for water service range in diameter from Y., an inch to 16 inches.
The Pressure on Plumbing varies through an extensive range. In cities
where dependence is placed upon the natural head at a distributing- reser voir, the pressure is often very light, while in cases where pumping- ma chinery is used and a head maintained in stand-pipes, or where the water is delivered into the main pipes directly- from pumps, the pressure may rise to above one hundred pounds to the square inch.
Gas-fittin,0,-.—Arrangements for the introduction of gas into buildings located in cities and large towns were formerly almost universal, and they are still very general, but during recent years they have to some extent been supplemented by, and intermingled with, devices pertaining to elec tric lighting.
ordinary methods of introducing gas are ranked among the simplest of mechanical operations, but they shOuld nevertheless be conducted with due regard for such requirements as are essential to safety and efficiency. Failure to secure an appropriate relation between the size and strength of the pipes used and the amount of gas consumed in an en rtire building and its various subdivisions may lead to disappointinomo gerous results. It is also important that all soldering of joints should be performed in a thorough manner, and that a judicious selection and adjust ment should be made of burners, chandeliers, and other fixtures.
Sel ordinary arrangement of the gas supply of the house consists, first, of au inlet-pipe of iron, bringing the gas from the street main to the meter, which is usually placed in a portion of the cellar as near the street as possible. From the meter an iron pipe passes up to the level of the first floor requiring a supply of gas. Here branch-pipes are led off to the various rooms, while the principal pipe is continued upward to the other stories as far as desired, and connections made with it which lead to all desired points on each story. In English practice, cast-iron pipes are used for diameters above 2 inches, and wrought-iron for those of smaller bore. In Paris the gas-pipes must be visible for their whole length, except when passing through a floor or a partition, when they must be let through a larger pipe having- both ends open. In the United States, strict regula tions were established in some of the American cities at the time gas was first introduced, but to a considerable extent their enforcement has been abandoned.