358,190. Cables. CALLENDER'S CABLE & CONSTRUCTION Co., Ltd., HUNTER, P. V., Hamilton House, Victoria Embankment, WATSON, J. F., Preston Lea, Woolwich Road, Abbey Wood, and BRAZIER, L. G., Hamilton House, Victoria Embankment, both in London, Aug. 11, 1930, Nos. 23988/30, 24953/30, 25491/30, 25624/30 and 1440/31. [Class 36.] A single core cable 1 is built up with impregnated layers of insulation 3 such as helically lapped paper on the conductor, the insulated core having a non- circular form in cross section, e.g. an elongated ellipse, a triangle or four-sided figure with rounded corners and, advantageously, slightly convex sides. The non-circular form of the core is preferably obtained by applying insulation to a non-circular conductor 2, or strips of insulation may be applied to a circular conductor so as to form a non-circular base on which the insulation layers may be wound. The conductor may be formed of a non-circular configuration which rotates about the conductor axis along its length as shown in Fig. 6. A lead sheath 6 surrounds the core and contacts lightly with a conductive layer 4 wrapped over the core insulation. The lead sheath may be non-circular to fit the core, or a circular lead sheath 6 may be applied, the clearance 7 thus formed being preferably filled by compound and a quantity of inert gas which may be contained in flexible walled vessels. Filling pieces may, however, be arranged round the core to enable a circular lead sheath to fit closely. A small radial clearance may be left between the core and the sheath, and, in order to maintain the layer 4 in electrical contact with the sheath 6, a metal tape 14 with springy projections 15, Figs. 4 and 5, may be wound on the core, the projections 15 extending inwardly towards the layer 4. The projections 15 may be produced by stamping up the centre part of a tape 14, or a metallized fabric or paper tape may be threaded through by a wire or metal strip. The tape 14 may be applied as an open helix. Three of the Provisional Specifications describe multicore cables of non-circular section with a space between the core and lead sheath which is preferably filled partly with compound and partly with inert gas, flexible vessels enclosing the gas and conductive layers with springy projections for bridging the space between the core and sheath also be referred to in connection with multicore cables. Specification 350,714 is referred to.