When the privy is to be used the rod is pulled up so that the antisplashing board rises to within about 1 inch of the surface of the water. The fecal material falls into the water, but this board prevents splashing. Before leaving the privy the person should sink the antisplashing board by pushing down the rod so that the fecal matter and the toilet paper will float free into the water.

Although some of the fecal matter floats, it is protected both from fly breeding and fly feeding in the following ways: First, by the automatically closing lid; second, by the water; third, by the film of oil; and fourth, by having the apparatus located in a screened place, which should be done for additional safety. The film of oil prevents the breeding of mosquitoes in the tank.

LH-WILDER

FIG. 27. A stationary-receptacle sanitary privy with a cement vault
arranged for convenient cleaning. (Original.)

The fecal material ferments in the water and gradually liquefies. Disinfectants must not be used in the liquefying tank because they stop the fermentation. When the level of the liquid is raised the excess flows into the effluent tank, where it is protected from insects by the cover and a film of oil. The effluent may be allowed to collect in this tank until it reaches the level of the connecting pipe, when it may safely be disposed of in any one of the following ways:

Burning. In cities, towns, and villages privy contents may be disposed of most conveniently, most safely, and most economically by burning with other refuse in an incinerator. At country homes also disposal by burning is the safest method; but because of lack of facilities at such homes it is usually not feasible.

Discharge into a sewer.-If a sewer is available, privy contents may be dumped through a manhole directly into it and the sewer flushed with water from a fire hose. In doing this precautions (grit cham

bers or gratings) should be used to prevent choking of the sewer with coarse insoluble matter. From a sanitary standpoint, the diluted privy contents are as safe for discharge through the sewer as is the sewage of the community.

Burial.-In small villages and country communities the disposal of privy contents by burial is usually the most available method that is practicable. The place selected for burial should be at least 100 yards away from any water supply and should not drain toward it.

FIG. 28.-An L. R. S. privy with an ordinary vinegar barrel used as a
liquefying tank and an iron pot for effluent tank. (Original.)

To take advantage of the natural agencies of purification in the soil and to protect underground sources of water supply as much as possible, the burial should be in the upper 2 feet of the soil. Furrows (such as are made by an ordinary plow) or narrow trenches should be used rather than large pits, so that the purifying agents of the soil will not be overworked. As an additional safeguard, disinfection of the excreta by heat or chemicals may be employed before such burial.

The effluent from the L. R. S. privy is particularly adapted to disinfection. If human excreta are disinfected by boiling, the matter is safe for use as a fertilizer, even near the dwelling.

The field used for the burial of untreated excreta should be one which is not to be cultivated for at least 6 months; and in sections where hookworm disease prevails a minimum of 12 months should be allowed. In cold climates trenches should be dug before the ground freezes. They should be ample to take care of privy contents during the winter and should be marked with stakes, so that they may be found even when covered with snow. The matter put into these trenches should be covered as soon as the ground thaws. Trenches for winter use should be about 2 feet deep. In open weather, the matter should always be covered immediately; the furrows should be from 6 to 12 inches deep; and the excreta scattered along the furrow, in a layer not more than 2 inches in thickness, and covered with 6 to 12 inches of earth.

FIG. 29.-Distribution of effluent from an L. R. S. privy into top soil. The effluent pipe is cemented into a glazed. (water-tight) terra cotta pipe which extends to the disposal ground. The effluent is distributed into the soil by means of open-joint drain tile. (Original.)

The use of a field for the burial of human excreta in this manner increases the fertility of the soil. This is particularly the case if the matter is given as much as 12 months to undergo thorough rotting.

The effluent from an L. R. S. privy is more readily purified by the natural agents of the soil than are crude excreta. It is liquid, and its volume is relatively small. It is therefore well adapted for direct disposal into the active subsurface soil. (Fig. 26.) The place selected for such disposal should be well away from (at least 50 yards) and not draining toward any water supply. The effluent may be conveyed under ground through a water-tight pipe for the necessary distance and then distributed into the soil by means of drain tile. The tile should be laid about 12 inches below the surface of the ground. If the soil is not porous, the distributing pipe máy be laid in a trench filled with sand or gravel. The increased fertility of the soil along the track of the distributing pipe may be used advantageously to cultivate an attractive hedge of rose bushes (fig.

29) or other shrubs or to cultivate a row of corn or other plants, the edible parts of which are produced well above the surface of the 'ground.

Disposal of Refuse.

There are two methods of disposing of refuse generally in use in cities-the mixed system and the separate system. In the "mixed" system ashes, waste paper, garbage, and all sorts of rubbish are placed together in one can and removed several times a week to an incinerating plant where it is burned. The combustible matter in the refuse is usually sufficient to evaporate the water in the garbage, so that the material is self-consuming and requires but very little additional fuel. Steam generated by the heat may be employed to heat buildings or to run power plants for the use of the city. As the garbage is mixed in with ashes and other waste materials in this method there is less odor and it is not liable to attract flies and mosquitoes.

When the "separate" system is used the ashes and other rubbish are kept in separate cans from the garbage. There should always be two cans for the latter, one to be washed and allowed to dry while the other is being used. Special care should be taken to see that the cans have tight-fitting covers, so that the garbage may not be a source of food for rats or a breeding place for flies and mosquitoes. In large cities this garbage, after being collected, is often taken to a reduction plant, where the grease is saved for the extraction of the glycerine and for making soap, while the solid material, known as tankage, is utilized as a filler for fertilizers.

Cleaning.

Buildings which are inhabited by human beings should be kept scrupulously clean, and in cleaning great care should be exercised to avoid the stirring up of dust, the bad effects of which have already been pointed out in connection with the ventilation of buildings. (See p. 19) Wooden floors of living rooms should be varnished or waxed and polished so as to present a hard glistening surface. Only the best quality of varnish should be used, as the cheaper grades are sticky and gather dust. The cracks of old floors should be filled, after which the floors should be planed or sandpapered and then varnished or waxed. Carpets give a homelike appearance to rooms, afford some protection from cold, deaden the sound, and, on account of their elasticity, are comfortable to the feet, but they are great collectors of dust and dirt and are therefore insanitary. They are also difficult to keep clean and favor the development of vermin. On account of these disadvantages many persons have given up the use of carpets.

Rugs are less objectionable, as they can be easly removed and cleaned on the outside of the building. Matting that is tacked down should never be employed, as large quantities of dust will collect beneath it, which is diffused in the air by persons walking across the floor. Kitchen and bathroom floors, and halls where marble is used, should be frequently scrubbed, using plenty of soap and water. Cement floors should be kept painted, as otherwise they give off a fine dust. Linoleum is very useful in kitchens and the halls of large buildings. It should be carefully laid, the floor first being thoroughly cleaned, a cement paste put on the floor, and the linoleum then carefully fitted in place. Heavy weights should be placed along the seams. If the linoleum is put down in this way no water will get beneath its surface, and it makes a very satisfactory covering for the floor, as it can be easily cleaned with a little soap and water. Calcimining should not be employed except in cellars and for outbuildings, as walls thus treated can not be cleaned without streaking the dust over the surface. Painting is the best treatment for walls; wall paper is objectionable because it is difficult to clean.

Great care should be exercised in cleaning a house to prevent the dissemination of dust. It is of no value to stir up the dust in a room, simply brushing it off of one place and letting it settle in another. For this reason dry sweeping and dusting should not be employed. Carpets should be cleaned with carpet sweepers or vacuum cleaners, and if necessary to use a broom the carpet should be taken out of the building, or, if this is impracticable, the windows of the room should be thrown wide open so that there will be a circulation of air to blow the dust out. A person using a broom in this way should have a piece of cheesecloth tied over the face to prevent, as far as possible, the inhalation of dust. Polished floors should be cleaned with woolen floor dusters. (See fig. 30.) Th dust sticks to these woolen brooms and is not scattered about the room as when a corn or hair broom is employed. The wool can be cleaned by washing it in hot soapsuds; after drying, it should be dipped in kerosene oil and permitted to dry again without wringing. Another method of treating these brooms is to place them in gasoline, to which an ounce of floor oil has been added to each quart. These brooms can now be purchased on the market prepared for use. If the floor is very dirty a hair broom should first be used with a sweeping compound, the latter usually consisting of sawdust or paper moistened with a little water or oil. The dust sticks to the sawdust and is thus prevented from being blown about the room, Walls should be cleaned with soap and water and frequently dusted with one of the wool dusters described above. Feather dusters and dry cloths should never be used for removing dust from furniture as