The two main classes of incinerators are, (1) those that are installed in the cellar and there burn the garbage, which is dropped in a chute through a hopper installed by the sink or elsewhere in the kitchen (somewhat the way mail is dropped into the mail box through its chute) and (2) the incinerators which look like oblongly high stoves placed in a recess in the wall or against the wall in the kitchen where the waste is stored and burned. The cellar incinerator is connected with the kitchen, etc., often through the flue and the waste is dropped into a little hopper. Of course, the installed type should, if possible, be put in with the connivance of the architect before the house is built as it is simpler than tearing up afterward. This type, of course, takes up less actual kitchen space. Some homes use a large incinerator in kitchens (stove type and small ones in pantry or laundry). OBJECTS The large installed incinerator should be able to burn up bits of paper, sweepings, old boxes, soiled rags, garbage, smelly waste and reduce them to sterile, odorless, clean ash. And if these things are not done without clogging up your flues with oily combustion residues, etc., you might as well burn your stuff in the kitchen stoves. The ash lift can be used for various things. The ordinary portable type is primarily for garbage but some get away with whatever is put in them. CONSTRUCTION POINTS In the construction of the portable incinerator, the one that is placed in the room and not below stairs, you must be sure it is so built that the heat from burning is not communicated to the room to heat it up. This means then that the maker must think of supplying the apparatus with sufficient insulation to retain the enormous heat generated inside which is somewhere around 1600 degrees Fahrenheit. Just as your ice box is insulated against the cold air getting out, and the warm air getting in, so must your incinerator be insulated. Besides, the lining of the incinerator must be durable and made to withstand not only the heat but the tremendous attack on its walls of chemical substances released in combustion. Sometimes fire brick is used but usually clay or metal is used in the portable types. Furthermore, the incinerator becomes a fire peril if the insulation and the lining is not 100% perfect. Again the devices of air intakes and outlets, etc., etc., are questions for the engineer. All that we are concerned with, is whether the apparatus does its work. ECONOMY The cost of operation is practically nil. The fuel used is gas or coal. Gas is the best method, the writer thinks. It takes only about twenty to thirty cubic feet of gas per burning, as the gas is needed only to start the operation and the evaporated garbage burns itself thereafter. Or should! There is a type of portable incinerator which needs no fuel, just burns by ignition of dry waste which burns the wet as it dries out. CAPACITY