A great many kinds of water-closets have been made and used, with various degrees of success. The old-fashioned pan-closet becomes easily clogged, allows matter to decompose in the receptacle under the valve, and, in spite of its being cheaper, should not be used. The long-hopper closet is also objectionable, for the same reason. A recent bulletin of the Maine State Board of Health, which gives the relative merits of the different forms now available, very directly and briefly, is here repeated:-- "The choice of a water-closet should be made from those which have the bowl and trap all in one piece, which are simple in construction, are self-cleansing, and have a safe water-seal. None should be considered except the short-hopper, the washout, the washdown, the syphonic, and the syphon-jet closets. "Short-hopper closets not many years ago were considered desirable, but other styles costing but little more are better. [Illustration: FIG. 63.--Washout water-closet.] "The washout closet (Fig. 63) has too shallow a pool of water to receive the soil, and the trap below and the portion above the trap do not receive a sufficient scouring from the flush. [Illustration: FIG. 64.--Washdown water-closet.] "The washdown closet (Fig. 64) is an improvement over the washout. Having a deep basin, a deep water-seal, smaller surfaces uncovered by water, and a more efficient scouring action, it is more cleanly. The washdown closet is really an improved short hopper. [Illustration: FIG. 65.--Syphonic closet.] "Of late years the principle of syphonic action has been applied to the washdown closet. Figure 65 shows the outline of a syphonic closet. It will be seen that the basin, as in the washdown closet, has considerable depth and holds a considerable quantity of water; but it differs in having a more contracted outlet. When the closet is flushed, the filling of this outlet forms a syphon, and then the pressure of the air upon the surface of the water in the basin drives the water into the soil-pipe with much force. At the breaking of the syphon, enough water is left in the trap to preserve the seal. [Illustration: FIG. 66.--Syphon-jet closet.] "In the syphon-jet closet (Fig. 66) there is added to the mechanism of the syphon closet a jet of water which helps to drive the contents of the bowl more rapidly into the outlet. These two closets, syphon and the syphon-jet, are preferable to those of any other style. Among other advantages they are more nearly noiseless than any other kinds. "Recapitulating, it may be said, while the short-hopper and the washout closets may not deserve absolute condemnation, the advantages of the washdown, syphon, and the syphon-jet closets are so much greater that they should be chosen in all new work."