"After the materials are properly mixed, this clay is turned by a suspended shovel into the buckets of the elevator, which are attached to an endless band, in which it is raised to the third floor of the building.
" Projecting from the third floor towards the second is the casting which contains the iron mould for the pipe. Into this the clay from the wet-pan is thrown, and an iron plunger, moved by the piston of a steam cylinder, which piston is at tached to the upper end of the plunger rods, descends verti cally, compressing the clay in the mould below.
" After the clay is thoroughly compressed in the mould, an iron table under the mould, attached to the upper end of a piston passing below the second floor, and forming, as it were, the bottom for the mould, descends with the pipe standing upon it. The alternate upward and downward motions of the piston which moves the plunger, and the piston which moves the table, are controlled by the operator on the second floor, where the pipes are removed from the mould.
"Pipes under five inches in diameter are, when taken from the mould, immediately removed to another part of the second floor, where they have placed in them a wooden frame of the proper length, to which their ends are trimmed off and then smoothed with leather. As those over five inches in diameter come from the mould, they immediately have their spigot ends trimmed off, and are then taken by an elevator to the first floor where their ends are finished up. These, with the smaller pipes from the second floor, are placed on end on the drying floor of the first story of the building, where they remain from three to six days, when they are ready for burning.
"Branches are made by placing the branch piece, while damp, upon the main pipe, and then trimming and shaping them.
"Traps are formed by hand in plaster-of-Paris moulds, which are made in halves, dividing lengthwise.
"The walls of the kilns are of brick and are 13 inches in thickness. The kilns are circular, the largest being, inside, 22 feet in diameter, and 8 feet high to the square, surrounded by a dome.
" The kiln is filled with pipes from the drying floor, placed on end. It is fired from eight fire-places at equal distances around the kiln. Gas coal is used. Inside, the products of combustion pass through short vertical stacks toward the top of the kiln, whence they are beaten back among the pipes, and finally escape through a flue built around the kiln near the bottom, and pass in an underground flue to the stack.
"At the proper stage of burning, which is ascertained by small test pieces of clay which may be drawn and examined, the attendant passes three times around the kiln, and each time throws into each fire-place a shovelful of common salt. By this the pipes are glazed.
"After the sealing of the kiln three days are required in which to fire up and burn, and three more in which to cool off and remove the pipes, which are inspected and are then ready for the market."