_Mathieson's Joint._--This somewhat complicated, though very effective mode of jointing, which is adopted in the English torpedo service, is shown at Fig. 37, in elevation and section. It consists of two ebonite cylinders _a_, _a_, through which the cables to be connected are passed. Within these cylinders an ebonite tube _b_, _b_ is placed, the ends of which are wedge-shaped, and which press against two vulcanite rings _c_, _c_; in the interior of this tube _b_, _b_ is the metallic joint _d_ of the two cables. The centre of the tube _b_, _b_ is of square section, and fits into a hollow of similar form in the cylinders _a_, _a_, the object of this being to prevent any twisting of the wires during the process of screwing up, which would be liable to injure the metallic joint _d_. The manner of making this joint will be easily understood from the figure. With this, as with all other temporary joints, it is advisable to form a half-crown in the cable, including the joint. _Beardslee's Joint._--This form of temporary joint when used with strand conductors, which are composed of a number of small wires, has been found to be exceedingly useful and effective, the only defect of such a joint being the liability of straightening the wires of the conductors should a direct strain be brought upon the wire extremities. Fig. 38 represents a section of this joint; it consists of an ebonite cylinder _a_, one end of which is solid, and the other open and fitted with a screw thread, into which is screwed a plug _b_; through both the plug _b_, and the solid end of the cylinder _a_, perforations are made just large enough to admit the insulated wires _c_, _c_; about half an inch of the extremities of these wires are bared and cleaned, and then passed, the one through the plug _b_, a disc of vulcanised india rubber _d_, and a metal disc _e_, and the end of the strand conductor turned back on the face of this metal disc, the other through the perforation in the solid end of the cylinder _a_, then through similar discs _d_ and _e_, and the end of the strand conductor treated in the same manner as the former one; then by means of the screw plug _b_, the two metallic discs _b_, _b_, and consequently the bare extremities of the strand conductors are brought into close metallic contact.