PLUMBING Plumbing occupies an important position among the trades as an application of Sanitary Science.
Sanitary science is defined by an eminent authority* as "that body of hygienic knowledge, which, having been sufficiently and critically examined, has been found so far as tested to be invariably true. Its phenomena are natural phenomena; its laws are natural laws; its principles are scientific principles." The same authority defines the sanitary arts as "those methods and processes by which the applications of the principles of sanitary science are effected," and would include plumbing with other practical arts of construction involved in sanitary engineering and architecture.
Having thus noted the position occupied in this broad field by the matters under consideration, we may define plumbing as the art of placing in buildings the pipes and other apparatus used for intro ducing the water supply and removing the foul wastes.
Historically, the plumber is primarily one who works in lead; but this definition would be a misnomer applied to the handicraftsman of to-day. While in time past, and even within the memory and practice of men now working at the trade, it suited the occupation designated as plumbing, the term "plumber" survives the transition from lead to iron more by reason of established usage than from its fitness to indicate the workman of the present.
Two score of years ago, traps and soil, waste, and supply pipes were in many localities almost wholly of lead ; and much of the larger pipe was hand-made. Lead was then everywhere more frequently used for all these purposes than it is anywhere in the country now. To-day, first-class plumbing is possible in any type of building with out employing a vestige of lead, and that, too, with fixtures and fittings regularly on the market. Lead, however, is still used to a marked extent in plumbing, principally for traps, pipe connections, calked joints, water-service pipes, tank linings, flashings, etc. Its retention for these secondary purposes is due generally to superior fitness; yet in some instances it is because of the style of connection provided on certain fixtures, or for other reasons independent of the merits of the metal. On the whole, its loss of prestige has been slow and impartial.
Indeed, those manually skilled in the manipulation of lead have often opposed the adoption of other materials sufficiently to retard sub stitution of the better.
Lead has unequaled merit for plumbers' use in specific instances; and if the trade has suffered by injudicious substitution of other material during its rapid evolution in recent years, time will adjust the error as the fitness of lead becomes apparent. For service lines in the ground, no other material lasts longer or gives more satis faction than lead, provided the use of lead is safe with the particular water which flows through it. For cold-water lines inside buildings, it answers well. Wood tanks properly lined with lead are, in many cases, the best for indoor storage.
Lead pipe is not self-supporting in any position, in the sense that iron or brass may be considered so; and the providing of reason-" ably permanent support for lead work is an expensive item. Lead pipe costs more than iron or brass, in every case; and the cost increases proportionally with the extra weight necessary for all but very light pressures; while ordinary merchant's iron pipe, or seamless brass pipe of iron-pipe size, will withstand the pressure of any municipal or private supply in America.
Lead does not serve well for hot water. The contraction while cooling appears not to equal the expansion from heating; hence the pipe deteriorates at the hottest points, usually showing weakness first near the reservoir in the kitchen, especially at bends, and finally crystallizing beyond repair at those points. So much trouble has been experienced with stove and range connections of lead, that lead pipe for this purpose has been entirely abandoned. The wish to install something better suited than lead for hot-water service, is in large measure responsible for the general adoption of other material. Hot and cold supply lines that are dissimilar in material, in diameter, in joints, and in fastenings, are so unsymmetrical and out of harmony in every way that no mechanic is willing to install them for a slight real or fancied betterment.