_Chequering Tools._—The tools used for chequering are very simple. Imagine a small saw, or rather two small saws about one inch or more long, made at the end of a straight steel shank. The form is given in Fig. 15. The double saw can be made by filing it as one thick saw and then cutting a groove lengthwise with it. In using, one blade first forms a groove and the other blade works the next cut; as the first cut is finished, another mark is being made while so doing. This insures equal width of the cuts. Care must be exercised in using them so as not to tear the wood. A fine cut, sharp edged, three square or a small half round file may be used to finish the work if desired. [Illustration: FIGURE 15.] _Nipple Wrenches._—Two forms of nipple wrenches are used, one for square and the other for two-sided nipples. The most serviceable of these are made from a straight rod of steel, with a cross handle and an opening at the opposite end to correspond with the square on the nipple. For the two-sided, a hole to receive the round part of the nipple where the cap goes on, may be drilled in a rod of steel and a slot filed across to receive the shoulders of the sides. The square shouldered kind must have a hole drilled of the diameter of the square, and then being heated a square punch of the size of the square is driven in. The nipples used for Government or military arms have the squares larger than sporting guns, and the wrenches are generally made of a flat piece of steel with a square hole made through from side to side at one end and squared to fit the tube. When made, harden and draw to a blue color for temper. _Portable Forge._—The following description of a “home made” portable forge shown in Fig. 16 is given by a contributor to the _Blacksmith and Wheelwright_: “In size it is two feet square and three feet high; it is made entirely of wood; the bellows are round and are sixteen and a half inches in size, covered then with the best sheep skins. The bed of the forge consists of a box six inches deep. It is supported by corner posts, all as shown in the sketch. Through the centre of the bottom is a hole six inches in diameter for the tuyere; this is three inches in outside diameter, and is six inches high. The bed is lined with brick and clay. It does not heat through. The bellows are blown up by means of two half circles with straps from a board running across the bottom, all of which will be better understood by reference to the sketch. In addition to protecting the bed by brick and clay, the tuyere is set through a piece of sheet iron doubled and properly secured in place. The hood which surmounts the forge may be made out of old sheet iron, and will be found sufficient for the purpose. The connection between the tuyere and bellows is a tin pipe.” [Illustration: FIGURE 16.]