The process of driving tube-wells resembles pile-driving, but with this distinction, that while piles receive the blows of the “monkey” on their heads, the tubes are not struck at all, the blow being communicated by the clamp, which receives the blow near the ground. The tube-well, as in ordinary use, is not intended for piercing rock or solid formations, but is quite capable of penetrating very hard and compact soils, and can be also successfully driven through chalk, breaking through the flints which may obstruct its passage downward. When solid masses of rock or stone are reached, special means of drilling have to be provided for it. When coming upon rock or stone, the best plan is to pull up the tube and try in another spot. This applies also when deep beds of clay are driven into; for, by going a little distance off, and testing again, in many cases water will be found. [Illustration: FIG. 178.] The operation is as follows: The first or pioneer tube, shown in Fig. 175 is furnished with a steel point of bulbous form, and perforated with holes varying from one-eighth to an inch, extending from 15 in. to 3 ft. from the point, Fig. 178. The enlargement of the point serves to clear a passage for the couplings by which the tubes are screwed together. On this tube the clamp Fig. 176 is held about 3 ft. from the point by two bolts; the clamp is of wrought iron with steel bushing screwed internally so as to form teeth to grip the tube. Next, the cast-iron driving-weight or monkey is slipped on to the tube above the clamp. The monkey is operated with ropes. _Sucker-Rod Couplings._ These couplings are usually made of iron galvanized and are used to connect the ends of wooden sucker rods for deep well pumps. Each half of coupling is secured to the end of wooden rods by three bolts; the ends of the couplings are joined by male and female threads in the usual way. Either bolts or rivets may be used to attach the rods to the couplings. (See Fig. 179.) [Illustration: FIG. 179.] POINTS FOR ERECTING AND OPERATING HAND PUMPS. _Foundation_—For the smaller sizes a foundation is not necessary, other than a good floor. With the large sizes it is advisable to have a substantial foundation. Concrete, well rammed into place, surmounted by a capstone, is as good as any. The foundation allows the pump to be run at a higher speed; a plan showing location of bolt-holes, position of flanges, and general dimensions, so that there may be no delay in setting the pump upon arrival at its destination. [Illustration: FIG. 180.] _Suction Pipe_—The suction pipe should be as short and direct as possible, avoiding all turns not necessary. Place a strainer and foot-valve, Fig. 180, on the suction pipe. It is better for the pump to have a slight suction except when hot water is pumped, than to supply the water to the pump under a slight head. _Discharge Pipe_—Make the discharge piping as straight as possible, using long bends.