[en] 4681. Hanson, A. P. Feb. 27. Telephone systems.-Relates to electric cables and the jointing and arrangement of the same in telephone exchange systems where a large number of conductors must be led to the switchboards &c. in a very small compass, each conductor or group of conductors being accessible at regularly-recurring intervals for making connection to the contacts, jack springs, or other apparatus employed. The cable consists of a number of conductors, bare or insulated preferably with a thin coat of varnish, arranged or held upon a layer of paper or the like insulating-material, which may be waterproofed, paraffined, or otherwise treated, or embedded in insulating-material such as paper pulp, cellulose, gutta-percha, or the like, openings or gaps being left to permit other conductors being joined to the cable wires, or through which the cable wires protrnde for connecting with terminals &c. The wires may be arranged singly or in pairs, the two of a pair being so spaced relatively to each other and to the other wires, or so twisted together, or regularly transposed, as to diminish or eliminate induction effects. In the form shown in Fig. 1, the cable wires a are glued or cemented to the paper c which contains openings e for making connection to the cable wires a'. The openings e may form a continuous diagonal slot, or completely sever the strip c into two parts. Instead of a longitudinal ribbon c, cross-strips may be employed. A second strip d may be glued or otherwise held on the first in order to keep the wires in position, and give more stability to the cable. In this case, it is not necessary to attach the wires a to the ribbon c. The layers c, d may be corrugated in any desired direction, in order to let the insulation touch the bare wires a, Fig. 4, in as few places as possible, and to give a certain thickness to the cable for properly spacing them to correspond with the thickness of the jacks or other apparatus, when the cables are laid one upon the other. In Fig. 5, each pair of wires a, b is wound helically round a piece of thick soft string, paper, or the like, or properly insulated wires may be twisted together, and, properly spaced, held between the layers c, d. Both wires a, b of each pair may be accessible at the openings e, or one accessible at the openings in the top layer c and the other at the openings in the bottom layer d. The wires a may protrude through the openings, Fig. 6, and be soldered to jack springs, contacts, or other wires, or the loops may extend just over the edge of the insulating- material c, and serve directly as contacts, being firmly held between layers of any suitable material or in any other way. Several of such cables may be superposed, forming banks of such contacts, each with several rows. Each wire of the cable may be completely enclosed, Fig. 7, by placing it in a pocket or longitudinal corrugation in the paper &c. which is then folded over in the manner shown. When the cables are placed one above the other, for use with multiple jacks in an ordinary telephone exchange, or the bank contacts of an automatic exchange, a sheet of metal may be placed between the several layers to prevent induction, or the cables sheathed or armoured in the usual way for the same purpose, or to render them more fire or damp proof.