least 3-64ths of an inch in thickness, and covered with a substantial braid. It must not readily carry fire, must show an insulating resistance of one megohm per mile after two weeks' submersion in water at 70 degrees Fahrenheit, and three days' submersion in lime water, with a current of 550 volts and after three minutes' electrification. (See List of Wires, page 202).

Section f. All joints must be soldered, even if made with the McIntyre or any other patent splicing device. This ruling applies to joints and splices in all classes of wiring covered by these Rules. RULE 12. INTERIOR CONDUCTORS:

Section d. Insulation that will be approved for interior conductors must be solid, at least 3-64th of an inch in thickness, and covered with a substantial braid. It must not readily carry fire, must show an insulating resistance of one megohm per mile after two weeks' submersion in water at 70 degrees Fahrenheit, and three days' submersion in lime water, with a current of 550 volts and after three minutes' elec

trification. (See List of Wires, page 202). RULE 13. ARC LAMPS:

Section c. The hand switch to be approved, if placed anywhere except on the lamp itself, must comply with requirements for switches on hanger boards as laid down in Section (g) of Rule 13.

Section f. An approved spark arrester is one which will so close the upper orifice of the globe that it will be impossible for any sparks thrown off by the carbons to escape.

RULE 15. OUTSIDE OVERHEAD CONDuct

ORS:

Section b. An approved fusible cut-out must comply with the sections of Rules. 23 and 24 describing fuses and cut-outs. The cut-out required by this section must be placed so as to protect the switch required by Rule 17.

RULE 16. UNDERGROUND CONDUCTORS:

Section b. The cut-out required by this section must be placed so as to protect the switch.

RULE 17:

The switch required by this rule to be approved must be double pole, must plainly indicate whether the current is "on or "off," and must comply with Sections a, c, d and e of Rule 26 relating to switches. RULE 18.

CONDUCTORS:

Section a. In so-called "concealed wiring, molding, and conduit work, and in places liable to be exposed to dampness, the insulating covering of the wire, to be approved, must be solid, at least 3-64th of an inch in thickness, and covered with a substantial braid. It must not readily carry fire, must show an insulating resistance of one megohm per mile after two weeks' submersion in water at 70 degrees Fahrenheit, and three days' submersion in lime water, with a current of 550 volts and after three minutes' electrification. (See List of Wires, page 202).

For work which is entirely exposed to view throughout the whole interior circuits, and not liable to be exposed to

dampness, a wire with an insulating covering that will not support combustion, will resist abrasion, is at least 1-16th of an inch in thickness, and thoroughly impregnated with a moisture repellent, will be approved.

Section b. Second paragraph. Except for floors, and for places liable to be exposed to dampness, Glass, Porcelain, metal-sheathed Interior Conduit, and Vulca Tube, when made especially for bushings, will be approved.

The last two named will not be approved if cut from the usual lengths of tube made for conduit work, nor when made without a head or flange on one end.

Section f. All joints must be soldered, even if made with the McIntyre or other patent splicing device. This ruling applies to joints and splices in all classes of wiring covered by these rules. RULE 21. SPECIAL WIRING:—

Section b. The insulating covering of the wire to be approved under this section must be solid, at least 3-64th of an inch in

thickness, and covered with a substantial braid. It must not readily carry fire, must show an insulating resistance of one megohm per mile after two weeks' submersion in water at 70 degrees Fahrenheit, and three days' submersion in lime water with a current of 550 volts after three minutes' electrification, and must also withstand a satisfactory test against such chemical compounds or mixtures as it will be liable to be subjected to in the risk under consideration.

RULE 22. INTERIOR CONDUITS:

The American Circular Loom Co. Tube, the brass-sheathed and the iron-armored tubes made by the Interior Conduit and Insulation Company, and the Vulca Tube are approved for the class of work called for in this rule.

NOTE. The use of two Standard wires (see page 202), either separate or twin conductor, in a straight conduit installation is approved in the iron-armored conduit of the Interior Conduit and Insulation Co., but not in any of the other approved