The steam-pipe kk connects the engine with the boiler. By means of the driving pulley, which carries the belt o o, motion is communicated to the band wheel m, and through it to all parts of the machinery. The throttle valve 77 is operated by a grooved vertical pulley from which an endless cord or wire m m, called the telegraph, extends to the derrick and passes around a similar pulley, n n, fixed upon the headache post z, also called a "life preserver." As its name indicates, the headache post is designed to save the driller a headache, or perhaps his life in case the wrist-pin should break, or the pitman fly off of it, while drilling, thus causing the derrick end of the walking beam to drop under the great weight of the suspended drilling tools, and endangering the safety of all within reach. This post is set upon the main sill immediately under the walking beam, so that if such an accident occur, the walking beam can fall but a few inches and do no harm.

The pulley n n, and that fixed upon the headache post being thus connected, the movement of one communicates a like motion to the other, and the driller by placing his hand upon the derrick pulley can operate the throttle valve and start or stop the engine, and increase or decrease its speed at pleasure, without leaving his position. The reverse link pp is also operated from the derrick by the cord q which passes over two pulleys, one fixed in the

engine house and the other in the derrick. The band wheel m receives its motion direct from the driving pulley of the engine to which it is connected by the belt o o. On, or near, the end of its shaft o, is the bull-rope pulley n, and to its other end is fastened the arm or crank o'. In this arm

a number of holes are drilled for the reception of the adjustable wrist-pin p, which thus may be easily moved from one hole to another to regulate the length of the stroke required in drilling or pumping.

As the band wheel communicates motion through the pitman q to the walking beam while drilling, to the bull wheels bb, by the bull rope rr, while running up the tools, and to the sand-pump reel by the friction pulley w, while sand-pumping, and as these movements are all used separately and at different times, it is necessary that the machinery be so constructed in its different parts that connection may be quickly made or broken, and one kind of motion substituted for another at pleasure.

The sand-pump reel w is put in motion by pressing on the lever v, which is joined by the connecting bar u to the upright lever t. This brings the face of the bevelled pulley w into contact with the face of the band wheel. It is simply a friction pulley and can be thrown in or out of gear, no

Fig. 5.

Fig. 6.

matter at what speed the band wheel may be revolving.

For a fuller illustration and explana

tion of the details of Figs. 1 to 3, we annex figures representing a complete set of irons belonging to a carpenter's rig.

Fig. 5.-Walking-beam stirrup.

Fig. 6.-Bolts for securing this by a wooden cap to walking beam.

Fig. 7 and Fig. 7 a.-Boxes for band-wheel shaft.
Fig. 8.-Band-wheel shaft, arm and flanges.

Fig. 9.-Centre irons for walking beam and samson posts.

Fig. 10 and Fig. 10 a.-Bolts for securing the saddle to walking beam.

Fig. 11.—Derrick or crown pulley.

Fig. 12.-Walking-beam hook, to hold temper screw. The next step in the operation is to place "a wooden conductor" through the earth and gravel down upon the bed-rock. The depth of the excavation necessary for this purpose varies of course according to the location of the well. The conductor (i, Fig. 1, Pl. I), is made of heavy planks spiked together, and must be carefully adjusted to the surface of the rock, to prevent the washing of the mud or gravel from entering the well at this point. The build

1 Whenever the rock is at a considerable depth, recourse must be had to a somewhat different method of operating. A pit is dug under the derrick for some distance down, usually until the process is interrupted by the influx of water, a conductor or pipe of some kind is driven into the earth at the bottom of the pit and forced through to the rock by means of an instrument resembling a pile-driver. The pipe may be of wood or iron, generally an iron pipe is used, called a driving pipe. It is prepared in joints of a certain length, and the joints are connected as the pipe is driven into the ground. The opera

ing of the several joints of the conductor, and placing it in position frequently form part of the contract with the carpenter. The derrick having been placed in position, the boiler and engine having been set up, and the belt con

tion is generally successful, but frequently the pipe runs upon a large stone, and in some cases, is bent or deflected from a vertical course. The pipe, however, having been successfully put down to the solid rock, the earth is removed from the interior.