Fig. 71 shows a stud-block, which is used for suspending tubing either for putting it down or for drawing it up. It consists of a block made to fit inside the end of the tube, and attached to the rods in the usual way. In the side of the block is fixed an iron stud for slipping into a slot, similar to a bayonet-joint, cut in the end of the tube, so that it may be thus suspended. Figs. 72 to 74 show various forms of spring-darts, and Fig. 75 a pipe-dog, for the same purpose. Sometimes a conical plug, with a screw cut around the outside for tightening itself in the upper end of the tube, is used for raising and lowering tubing. Figs. 76 and 77 are of tube clamps, and Fig. 78 tongs for screwing up the tubes. Fig. 79 is of an ordinary form of sinker's bucket. [Illustration: Spring-dart. Fig. 72.] [Illustration: Spring-Dart. Fig. 73.] [Illustration: Spring-dart. Fig. 74.] [Illustration: Pipe-dog. Fig. 75.] [Illustration: Tube Clamp. Fig. 76.] [Illustration: Tube Clamp. Fig. 77.] [Illustration: Tongs. Fig. 78.] [Illustration: Sinker's Bucket. Fig. 79.] Fig. 80 is a pipe-dolly, used for driving the lining tubes; the figure shows it in position ready for driving. When a projection in the bore-hole obstructs the downward course of the lining tubes, the hole can be enlarged below the pipes by means of a rimer, Fig. 81. It consists of an iron shank, to which is bolted two thin strips, bowed out in to the form of a drawing pen. The rimer is screwed on to the boring rods, and forced down through the pipes; when below the last length of pipe the rimer expands, and can then be turned round, which has the effect of scraping the sides and enlarging that portion of the hole subject to its operation. Fig. 82 is of an improved form of rimer, termed a riming spring. It will be seen that this instrument is much stronger than the ordinary rimer, in consequence of the shank being extended through its entire length, thus rendering the scraping action of the bows very effective, whilst the slot at the foot of the bows permits of its introduction into, and withdrawal from, the tubing. [Illustration: Pipe-dolly. Fig. 80.] [Illustration: Rimer. Fig. 81.] [Illustration: Riming Spring. Fig. 82.] In England, for small works, the entire boring apparatus is frequently arranged as in Fig. 83, the tool being fixed at the end of the wrought-iron rods instead of at the end of a rope, as in the Chinese method. Referring to Fig. 83, A is the boring tool; B the rod to which the tool is attached; D D the levers by which the men E E give a circular or rotating motion to the tool; F, chain for attaching the boring apparatus to the pole G, which is fixed at H, and by its means the man at I transmits a vertical motion to the boring tool. [Illustration: Boring Apparatus. English, for Small Works. Fig. 83.]