This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
In general, the ideal of any kind of plumbing fixtures consists of a bowl, tub or closet in one piece, supplied by a sure and quick flow of water, and emptied by a simple and ample discharge. The superintendent should see that the quality and pattern are as called for by the specifications, that they are perfect in every respect and set up in a workmanlike manner. In regard to closets there are several types from which to choose. The simplest of these is the "short hopper". This consists of an earthenware bowl (Fig. 46), and a trap, the latter being sometimes made of earthenware, and often a lead or iron trap to which the bowl is bolted (Fig. 47), the contents being washed into the soil pipe by a discharge of water all around the top rim, which is curled over and perforated or brought to a narrow opening.
An improvement of this form known as the "wash down" closet (Fig. 48), in which a deeper trap and a larger water area is formed than that made by the regular hopper and trap, is a well-known pattern. This closet requires a large flush of water to remove the contents and is somewhat noisy on that account. To overcome this and to assist in the discharge as well, there has been invented what is known as the "syphon-jet" closet. (Fig. 49.) In this closet a small inlet in the bottom of the basin is connected with the flush pipe, so that when the bowl is flushed a jet of water shall be projected upward which assists in removing the contents of the basin and also in filling the outlet, which is contracted somewhat, in order that the flow of water may fill it completely and produce on a large scale the vacuum as previously described in relation to the S-trap, so that the pressure of the air upon the water in the basin helps to push out the contents. An objection to the jet is found in houses which are to be left unoccupied during the winter, since the water which is to be thrown out to form the jet remains in the bowl even when the trap has been emptied, and requires especial attention. Another form of syphon closet produces the syphonic action without the jet by making a sudden turn in the outlet pipe, which causes the flush of water to completely fill the pipe and produce a vacuum with the same result as described. A type of closet called the "washout" closet was formerly much in vogue (Fig. 50), but it is not so positive in its action as the others described, and is less popular than formerly.
Fig. 46. Hopper.
Fig. 47. Hopper and Trap.