Among the many requirements of a perfect system of plumbing may be mentioned:

First

An adequate supply of water sufficient in volume and pressure to flush the various fixtures.

Second

Types of fixtures that are made of porcelain enamel, and are set open, and located in well lighted, properly ventilated rooms,

Third

A system having waste pipes large enough to carry off all waste matter discharged into them, yet not so large as not to be self-cleaning,

Fourth

A system of ventilation so planned as to properly ventilate every portion of the drainage system.

Fifth

A quality of piping that will neither corrode easily nor be affected by sudden changes of temperature, and the joints of which can be made as strong as the pipes themselves.

Sixth

A properly graded, perfectly gas and watertight system that will discharge by gravity.

Seventh

A system uniformly supported throughout its entire extent, that can neither settle nor swing nor pull on any of its branches.

Eighth

A system of installation that provides turns and offsets of easy angles; that connects its branches at such an angle as not to interrupt the flow of sewage in the main, and that provides clean-outs at such points that the inside of the drainage system is accessible throughout its entire extent.