Into the iron drain the vertical soil and waste pipes enter by means of either quarter bends or by a Y branch with an eighth bend.*

* As regards the exact meaning of the terms drain pipe, soil pipe, and waste pipe, I quote the following clear explanation from the "Sanitary Engineer," Vol. 4: "The drainage system of a house, including the pipes or channels of any kind connecting it with the sewer or cesspool, may be divided into two parts-first, that part which is chiefly outside the house walls, and second, that which is generally inside the house. The first is called the house drain, or simply drain. and conveys the whole body of wastes from the house, including both the discharges from water-closets and urinals, and from baths, basins, sinks, etc., to the sewer or cesspool. The drain is practically horizontal, and may be considered as terminating either at the house wall, or at the most remote point at which it receives the pipes From any fixtures. The word drain is, however, also used in another sense as distinguished from sewer. It then means the pipe or Channel Which conveys only rain or ground water, as distinguished from sewage. An example of this kind of drain is the separate system of pipes, used to convey only rain water in some towns and the tile pipe commonly employed in draining wet lands.

"Thai part of the house drainage system which is generally inside the house, Including the pipes from the Various fixtures, is made up of soil pipes and waste pipes. Soil pipes arc those pipes which receive human excrete from water closets and urinals, and they are Still called soil pipes, even if they also receive the wastewater from baths, basins, etc. On the other hand. waste pipes are those which receive only the waste water from these latter, but not the discharge from water closets and urinals. The waste, pipes of a house may either enter the house drain independently

The best material for soil and waste pipes is cast iron. All cast iron pipes used in house drainage should be thoroughly sound, of a uniform thickness throughout, and must allow of ready cutting without splitting. The inside should be truly cylindrical and of smooth finish. The thickness of ordinary (so-called light) soil pipe is about 1/8 of an inch for 2, 3 and 4-inch pipes, and 5/32 to 3/16 of an inch for 5 and 6 inch pipe. For all large public or private buildings I should always insist upon the use of extra heavy soil pipe, which is about double as thick as the ordinary pipe. The weights of extra heavy pipe are about as follows:

or join the soil pipe first and discharge their contents through it into the drain. As distinguished from the drain the soil pipes and waste pipes, at least for the longer lengths, are generally vertical."

Great care should be exercised by plumbers, architects, plumbing inspectors and sanitary engineers in regard to the uniform thickness of iron soil pipe. The writer has lately seen specimens of extra heavy soil pipe where the pipe was almost as thin as a knife-blade on one side, while it had far more than the required thickness on the other side, the weight being as specified. Measuring the thickness of iron drain pipes by a pair of calipers should be recommended, but I am not aware thai it is done at all now.

Iron soil pipe, the inside of which has been made smooth by dipping the pipe into a hot solution of coal-tar pitch, is superior to ordinary iron pipe. This coating, when applied to the outside of the pipe, forms a good preventive against rust or corrosion, and is better than any paint applied to the iron. Where economy is no object, the enamelled pipe may be used, which has a very smooth inside surface, thus securing to well-flushed soil pipes the greatest possible cleanliness. Whether iron pipes are coated with coal tar pitch or enamelled, it is necessary, before applying either of these protective coats, carefully to test each pipe for defects, sand holes or cracks, by the hammer test. The coating may effectually cover these defects and render detection difficult.

Iron pipes are manufactured in lengths of 5 feet, with hub and spigot end, or else with double hub.

The iron works manufacture not only straight soil pipe, but a large number of fittings, such as quarter bends, eighth bends, sixth bends, sixteenth bends, T branches, Y branches, double Y branches, half Y branches, offsets, single and double hubs, increasers, reducers, etc, to enable the plumber to make all possible connections and lines with iron pipe.

In England lead pipe is preferred for soil pipes. According to one of the best English authorities on plumbing * the advantages claimed for lead pipe are briefly as follows:

* S. Stephens Hellyer, "The Plumber and Sanitary-houses ," 2d edition.

1. It is smoother, cleaner, not so corrosive; more durable.

2. It can be bent to suit any position; it is more compact.

3. Its joints are more to be depended upon than iron pipe joints.

4. Urine, being very corrosive, acts more on iron than on lead.

5. Iron pipe rusts on the outside, and painting iron pipes, to prevent it, is expensive, and is generally not done thoroughly at the back of the pipe.

6. Lead branch wastes or traps cannot easily be joined to iron pipe.

7. Iron pipe does not allow caulking joints with lead, therefore cement is used for the joint.

From all this I disagree, for:

1. Tarred or enamelled iron pipe is fully as smooth as lead pipe, and the iron pipe is thereby well protected from corrosion.

2. The above enumerated variety of special fittings enables the plumber readily to adapt bis iron pipe to almost any position; moreover I do not see why iron pipe should take up a great deal more room than lead pipe of same bore.

3. Well caulked joints of heavy iron pipes are just as sound and trustworthy as wiped joints in lead pipes, and any good mechanic is able to make them.