[Electric engineering.] . rubber-covered wires, not smallerthan No. 14 B. & S., which should preferably be twistedtogether when the drop is over 3 feet. These wires shouldbe soldered direct to the circuit wires, but supported inde-pendently of them. 19. Fig. 5 shows a waterproof globe for use whereinflammable gases may exist. In wiring damp cellars, it isespecially desirable to have the lampsdivided among several small circuits,so that the blowing of a fuse will notput out many lamps. In such work,rosettes should never be used, butthe drop wires should be soldereddirect to, but preferably not
[Electric engineering.] . rubber-covered wires, not smallerthan No. 14 B. & S., which should preferably be twistedtogether when the drop is over 3 feet. These wires shouldbe soldered direct to the circuit wires, but supported inde-pendently of them. 19. Fig. 5 shows a waterproof globe for use whereinflammable gases may exist. In wiring damp cellars, it isespecially desirable to have the lampsdivided among several small circuits,so that the blowing of a fuse will notput out many lamps. In such work,rosettes should never be used, butthe drop wires should be soldereddirect to, but preferably not sup-ported by, the • line wires, and thejoints should be thoroughly wrappedwith insulating tape. The cut-outsshould-be placed outside the cellars, ina dry place if possible, otherwise theyshould be placed in waterproof boxes. 20. Rubber-Covered Wire.—In all kinds of work, except open zvorkin dry places, rubber-covered wire mustbe used. The Underwriters requireit to comply with the following speci-fications : fkTT. 20 INTERIOR WIRING. § 27 Rubber-Covered Wire.— a. Copper for conductors must be thoroughlytinned. Insulation for voltages between 0 and 600: b. Must be of rubber or other approved sub-stance and be of a thickness not less than that givenin the following table for B. & S. gauge sizes: From 18 to 16, inclusive, i » 3 2. From 14 to 8, inclusive, 3 64 From 7 to 2, inclusive, 1 n1 6 From 1 to 0000, inclusive, 5 a 6 4 From 0000 to 500,000, C. M. 3 I3 2 From 500,000 to 1,000,000, C. M. 7 64 Larger than 1,000,000, C. M. 1 8 Measurements of insulating wall are to be madeat the thinnest portion. e. The completed coverings must show an insu-lation resistance of at least 100 megohms (100,000,-000 ohms) per mile during 30 days immersion inwater at 70° F. d. Each foot of the completed covering mustshow a dielectric strength sufficient to resistthroughout 5 minutes the application of an electro-motive force of 3,000 volts per -£T inch thickness ofinsulation under the follo
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