construction, and may be operated by or independently of the machine.

Instead of a double pump, as shown, a single pump may be used, although the former is preferable, as it gives a uniform movement to the plunger.

By varying the quantity of fluid fed to the pump, for which purpose the pipe 36 is provided with a regulatingcock, as shown in Fig. 161, or pumps, it will readily be seen that the speed of the plunger can be varied at pleasure. This is an important feature, as in making tile of large size the plunger can be operated successfully at a much greater speed than when small-sized tile are being made, and also because by this means the amount of tempering to which the clay is subjected can be easily regulated.

Fig. 171 shows an old style of pipe machine much in use in Europe and in this country for forming large-sized pipes.

The exterior cylinder contains a second cylinder which holds a given quantity of clay. By the rack the clay is forced by the piston through the die upon a balanced table, which is forced down, and when the proper length of pipe is formed, the belt is shifted, and the machine stops; the length of pipe is cut off by the wire shown under the cylinder.

The pipe is removed, the table raises, and the machine is again set in motion, and the operation continued as before, and when all the clay in the cylinder has been used, the rack is reversed, the plunger drawn entirely out, and the cylinder, which moves on pivots, is tilted, to receive another

charge of clay, then restored to its vertical position to be again quickly emptied. This class of machines is as clumsy as it is unprofitable; they cannot be run, on an average,

for more than one-quarter of the day, the other three-quarters being lost in the stops of the machine, which are too long, as well as too often, owing to the awkward construction of some of the parts.

SECTION IV. MACHINES FOR FORMING SOCKETS ON AND MAKING CURVED EARTHENWARE PIPES.

The machine shown in Figs. 172 to 178, and that shown in Figs. 179 to 181 are the inventions of Mr. Horace B. Camp.

The first invention shown in Figs. 172 to 178 has relation to that class of machinery for making pipes of clay or other plastic material by pressing it through an annular orifice between an outside die and an inside core, and its object is to form sockets on the end of sections of such pipe when the pipe is caused to curve as it issues from the orifice.

In order to present the distinctive features of the invention, it is proper to state that ordinarily to form such sockets on sections of straight pipe, the outer die is prolonged beyond the point of discharge of such length and inside shape as to form the outside of the desired socket. When, however, the pipe curves as it issues from the orifice, this device is impossible, as the issuing pipe encounters the edge of this socket-die and is destroyed. To obviate this difficulty, Camp constructs the socket-die separate from the other parts of the machine, in the form of a ring, divided into two parts, so as to permit of its being removed: and the first part of this invention relates to the method of holding this severed ring firmly in place until the socket is formed, which consists in fitting its upper edge into a groove in the lower face of the outside die, and its lower edge into a groove in a flange projecting from the base of the die, which forms the inside of the socket; and the second part of the invention relates to a combina

tion of arms and links for manipulating the parts of the ring.

For the purposes of this description, we adopt the following nomenclature :

That part of the pipe-press which forms the outside of the annular orifice through which the pipe issues-the outside die. The piece suspended centrally within this, and which forms the bore of the pipe-the core. The die which forms the inside of the socket-the lower die; and the severed ring which is interposed between the outside die and the flange of the lower die, and forms the outside of the socket -the ring.

Figure 172 is a sectional view of a portion of the lower part of a pipe-press, wherein A is the outside die, and B the core; the outside die A having a groove S in its lower face to receive the upper edge of the ring.

Fig. 173 is a central section of the ring C, divided in half at the line a (a plan of which is shown in Fig. 178), and having its upper edge turned to accurately fit in the groove S, in the outside die A, and its lower edge fitted in the same manner for the groove R of the flange of the lower die D.

Fig. 174 is a side view of one of the hooks H.

Fig. 176 is a plan and Fig. 175 a section at the line xx of the lower die D. Upon alternate sides of the flange of this die are two lugs d d, which lock into hooks HH attached to the outside die A, and hold the several parts together while the socket is formed.

In operation the lower die D, by means of the collar E

projecting from its base, rests upon a following rod (not shown), which moves in the line of the axis of the press. The ring C is then placed thereon, with its lower edge fitting into the groove R. The whole is then raised to the press, the upper part of the lower die D joining, and forming a continuation of the core B, and the ring Centering into the groove S. The lower die D is then revolved until the lugs d d lock into the hooks H H, as shown in Fig. 177, the whole forming a complete mould for the socket. When the socket is formed the lower die D is withdrawn, and the ring C separated and removed.

To facilitate the manipulation of the ring C the inventor attaches to the segments thereof the arms LL' (see Figs. 177 and 178), hinged upon the wrist Fattached to the bar P. Upon the wrist O, journaled in the bar P, are fastened