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great length. The resistance of a long, narrow object perpendicular to direction of motion is greater than that of a more symmetrical form. The experimentally determined value of the coefficient of resistance is 0.0029 for stranded cables and 0.0026 for smooth wires. K is almost in› 

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dependent of the diameter for all sizes of wire and cable. Stranded wire or cable ha~ a resistance about 14 percent greater than solid wire. 

(a) The above discussion relates only to wires and cables perpendicular to the wind direction or direction of motion. . When a wire or cable is inclined to the perpendicular its resistance is very much decreased as the air flows around it in more uniform stream› lines or in a more gradual curved path. An inclination of about 30° from the vertical reduces the resistance 20 percent and an in› clination of• 45° reduces the resistance 50 percent. 

(b) When two wires or cables are close together and placed one just behind. the other there is a reduction in resistance due to shielding of the second wire by the first. If they are placed very close together their combined resistance is considerably less than the resistance of one wire .alone, as the two wires have the effect of an increased fineness ratio. If they are spaced more than 3ljz di› ameters their combined resistance becomes greater than a single wire but is still less than the resistance of the two wires tested separately. This shows that if two wires or cables are close together (within 5 diameters 

of each other) it is very advisable to put a filler block in between them, thus preventing the air from flowing in between them and . giving them the advantage of a single member of high fineness-ratio. If the two wires are streamlined in this way their combined resistance can be kept down to about 50 percent of the resistance of a single wire until their fineness ratio becomes greater than seven. The high value of the resistance caused by wires and cables immediately sug› gests reduction of wires and cables to the minimum by means of refinements in design and arrangement. - . 

