the round trip to the dumping place at sea and back again consumes twenty-six hours. The refuse is not only a total loss, but a cause of heavy expense to the city. It also makes possible a nuisance at near-by beaches, and the whole result is a waste of materials, time, and labor.

Incineration. The phrase "garbage incineration" is suggestive of the old and obnoxious garbage dump with its occasional smoldering fires, which had to be maintained at a considerable distance from habitation because of its offensive odors. The modern incinerating plant, however, should never be a nuisance. In Rio Janeiro there is an incinerating plant in the civic center, housed

in a beautiful building. Properly handled such a plant should emit no odors.

In Europe incineration is very successfully carried on. The wastes are all carried to the incinerators or "destructors," and burned to a harmless clinker in the great furnaces. Refuse carts are driven up an inclined roadway leading to a tipping platform, from which their loads are fed directly into the furnace.

Courtesy of the Nye Odorless Crematory Co. A MODERN INCINERATING PLANT Garbage carts and trucks drive up the

roadway to the upper floor of the building to dump their loads into the fire chamber. The ashes are removed from the two doors on the ground floor.

Three classes of incinerators are in use in this country. There is a small-scale type which is successfully used in private houses, apartment houses, and hotels, and operated by coal or gas. If properly handled it is an odorless and efficient substitute for the garbage can.

There is also a low-temperature incinerator, which has been

successfully used at army cantonments, and is now being installed by many towns and small cities. No fuel is needed to run it, for the combustible material in the garbage is sufficient to keep the fires going. This incinerator consumes everything except glassware, pieces of metal, and crockery. Though the ash remaining may be used to fill in land, it is of little value.

Then there are the large-scale high temperature destructors which have brick walls that accumulate a tremendous heat, and destroy everything. They render all gases innocuous, and resolve the ashes into a clinker that can be made into useful brick.

In the case of both the large-scale incinerator and the destructor the cost of operation is small, much less than that of carrying wastes out and dumping them at sea. More than fifty cities in the United States own and operate their own incinerating plants; others dispose of their garbage in incinerators owned by the city but operated by private individuals; still others in incinerators both owned and operated by contractors.

Reduction. Reduction is the process of sterilizing wastes under pressure. The refuse is literally cooked in enormous vats. During this steaming process the oils and fats are separated from the rest of the mass and rise to the surface. Here they are skimmed off. The harder materials that remain are rolled flat by huge presses, and then pulverized, making an excellent fertilizer. The oils and fats are sold to be used in making products as varied as axle grease, soap, munitions, and perfumes.

The best thing that can be said in favor of the reduction process is that it reclaims more useful material from wastes than does any other method of disposal. As much as twenty per cent. of the weight of garbage can be reclaimed by this process and sold. The most serious disadvantage in connection with the reduction process is that disagreeable odors usually accompany it. This nuisance has been lessened by modern methods of handling. In the Cobwell plants the garbage is boiled in huge air and gas tight vats called "reducers." Two valuable products result from this process: a brown sterile

grease that makes soap and glycerine, and a dry, sterile fertilizer. Los Angeles, Rochester and Syracuse have recently installed Cobwell reduction plants.

Ashes and Rubbish. Ashes and rubbish, on permit from the Board of Health, are frequently used to fill in low lands and marshy places, or even

to make islands. The use of wastes to fill in marsh sections has two advantages; it makes habitable land out of that which was useless before, and it reduces the nuisance of mosquitoes that breed in marshy places. Rikers Island in the East River, New York, is an island made partly of ashes and street refuse, hemmed in by a substantial sea wall. Making Money on Wastes. Cities are increasingly taking ad

Courtesy of Mr. Henry C. Allen REDUCER ROOM, COBWELL REDUCTION PLANT, ROCHESTER, N. Y.

The garbage is lowered through a round chute into one of the cylindrical machines. When full, the machine is sealed by its cover. Once the garbage goes in it does not come out until it has given up all of its water and its grease and has been converted into a dry, sterile fertilizer.

vantage of their opportunities to realize profits from the disposal of wastes. Contractors pay for the privilege of sorting rubbish at the dumps and taking out bottles, leathers, paper, cans, and other articles that may be used again. Ashes are used to increase the value and extent of city-owned land. The clinker that is produced by the high temperature destructor is sold to be made into brick. The heat which is generated by the burning of wastes in incinerators may be used to produce steampower. In Minneapolis this heat-energy is used to light and heat the city workhouse and the tuberculosis hospital. In Buffalo it serves to operate a sewage pumping station.

The most profitable method of waste disposal is that of reduction. A considerable percentage of the weight of garbage can be reclaimed by the reduction process and sold in the form of grease and fertilizers. It has been estimated that during 1919 the garbage produced by three boroughs of New York City amounted to 324,425 tons. Put through the reduction process, instead of being dumped at sea, this garbage would have yielded over 3.5 per cent. of grease, that is, fats and oils, and more than 15 per cent. of tankage, or fertilizer. Grease was then worth about $250 a ton, and tankage $15 a ton. So the reclaimable value in this garbage alone, exclusive of all other refuse, amounted to more than three and a half million dollars. This does not take into consideration the cost of extracting the value from the garbage. But it is estimated that with all costs of collection and disposal deducted, the city would have realized from the garbage a million and a quarter dollars to add to the revenues for that year.* In nearly half of the cities in the United States where garbage disposal is delegated by the city to private contractors, it is done by the reduction process. The private contractor is apt to handle such an undertaking by the most profitable plan.

8. ADMINISTRATION

In most communities of the United States, street cleaning and the control of highways, sewers, refuse collection and disposal are functions of the Department of Public Works. Few cities handle the whole problem of disposal. In most communities part, if not all of the work is done by contractors, more or less under city supervision.

Usually contractors who are building houses, and the proprietors of slaughter houses, markets, factories, and even hotels and restaurants, must dispose of their own refuse. As recently as 1909, forty-five cities, including San Francisco, Omaha, Seattle, and Des Moines, left to the householder the

*"City Loses Riches Yearly by Dumping Waste at Sea," by William A. Bassett, in the New York Evening Post, July 1, 1920.

entire burden of garbage collection and disposal, and in almost as many other cities, the responsibility was divided between the city and the householder. But nearly everywhere the Board of Health supervises the work and lays down regulations as to how the collection and disposal should be done, even to the kind of wagon to be used. There is a plain tendency, however, to consider the disposal of wastes a community function; and most large cities assume full charge. Experience shows that the individual householder cannot be depended upon to be both thorough and regular in disposing of his own wastes. There is a growing opinion that an undertaking so important to public health should be organized and operated by the community.

In Chicago, Boston, New York and Philadelphia, and a number of other large cities, the cost of building sewers is paid by the assessment of a special tax upon the property owners who will be directly benefited. In some cities the property owner pays a percentage of the cost, while the city assumes the balance. In others, the city is divided into sewer districts, and the cost of new sewers is paid for by a general property tax levied on all the property owners of each district, whether or not they directly benefit by the sewers.

A builder who wishes to connect a house with a street sewer must obtain a permit from the city. Some cities allow only city employees to make these connections, but usually licensed plumbers, drain layers, or sewer tappers may do so. This precaution is in order to make sure that the connections are properly made, and thus to protect the health of the residents of the neighborhood.

When a city's sewage pollutes a stream so that the water supply of a neighboring community is endangered, the state courts can be appealed to in order to have the pollution stopped. The United States Bureau of Public Health Service makes a study of sewage disposal in various sections of the country. Where the disposal of sewage results in any danger to water supply, the Bureau recommends changes in the system.