the gas piping or fixture shall be in electric connection with the gas-lighting circuit, and the wires used with the fixtures must have a non-inflammable insulation, or, where concealed between the pipe and shell of the fixture, the insulation must be such as required for fixture wiring for the electric light.

The whole installation must test free from the "grounds," and the two installations must test perfectly free from connection with each other.

ELECTRIC HEATERS.-Must, if stationary, be placed in a safe situation, isolated from inflammable materials and be treated as sources of heat. Must each have a cut-out and indicating switch, and have the attachments of feed wires to the heaters in plain sight, easily accessible and protected from interference, accidental or otherwise. The flexible conductors for portable apparatus, such as irons, etc., must have an approved insulating covering, and each heater must be provided with name-plate, giving the maker's name and the normal capacity in volts and

amperes.

DECORATIVE SERIES LAMPS.-Incandescent lamps run in series shall not be used for decorative purposes inside of buildings, except by special permission in writing from the Inspection Department having jurisdiction.

TROLLEY WIRES, RAILWAY POWER PLANTS, LIGHTING AND POWER FROM RAILWAY WIRES.Trolley wires must be no smaller than No. O. B. & S. copper, or No. 4 B & S. silicon bronze, and must readily stand the strain put upon them when in use, must have a double insulation from the ground (in wooden pole construction the pole will be considered as one insulation), and must be capable of being disconnected at the power house, or of being divided into sections, so that in case of fire on the railway route the current may be shut off from the particular section and not interfere with the work of the firemen (this rule also applies to feeders); and they must be safely protected against contact with all other conductors, by separate insulated guard wires directly placed so as to afford full protection from falling or sagging wires.

Railway power plants must be equipped in each feed wire before it leaves the station with an approved automatic circuitbreaker or other device, which will immediately cut off the cur

rent in case of an accidental ground. This device must be mounted on a fireproof base, and in full view and reach of the attendant.

Lighting and power from railway wires must not be permitted, under any pretense, in the same circuit with trolley wires with a ground return, except in electric railway cars, electric car houses and their power stations; nor shall the same dynamo be used for both purposes.

Lighting from trolley wires is forbidden because of the danger of introducing into a building a high-potential circuit (often over 500 volts) which has so much capacity back of it and which is thoroughly connected with the earth on one side. Lighting from lower voltage trolley wires is also forbidden on account of the ground connection.

Electric equipment of car houses must have the trolley wires securely supported on insulating hangers. Must have the trolley hangers placed at such distance apart that, in case of a break in the trolley wire, contact cannot be made with the floor. Must have cut-out switch located at a proper place outside of the building, so that all trolley circuits in the building can be cut-out at one point, and line circuit-breakers must be installed, so that when this cut-out switch is open the trolley wire will be dead at all points within 100 feet of the building. The current must be cut out of the building whenever the same is not in use or the road not in operation. Must have all lamps and stationary motors installed in such a way that one main switch can control the whole of each installation-lighting or power-independently of main feeder-switch. No portable incandescent lamps or twin wire allowed, except that portable incandescent lamps may be used in the pits, connections to be made by two approved rubber-covered flexible wires properly protected against mechanical injury; the circuit to be controlled by a switch placed outside of the pit. Must have all wiring and apparatus installed in accordance with rules for constant-potential systems. Must not have any system of feeder distribution centering in the building. Must have the rails bonded at each joint with not less than No. 2 B. & S. annealed copper wire; also a supplementary wire to be run for each track. Must not have cars left with trolley in electrical connection with the trolley wire.

MARINE WORK.-Generators must be located in a dry place, have their frames insulated from their bed-plates, be provided with waterproof covers and be provided with a name-plate giving the maker's name, the capacity in voltage and amperes and normal speed in revolutions per minute.

Wires must be supported in approved moulding or conduit except at switchboard and portables, and no wire must be larger than No. 12 B. & S.; if a greater carrying capacity is required, the wires must be stranded. No single wire smaller than No. 14 B. & S. must be used except in fixture. Stranded wires must be soldered before being fastened under clamps or binding screws, and when they have a conductivity greater than No. 10 B. & S. copper wire they must be soldered into lugs. Splices or taps in conductors must be avoided as far as possible, and all joints must be properly made and covered with waterproof tape and coated or painted with a waterproof compound. For moulding work the wires must have an approved insulating covering, and when passing through water-tight bulkheads and through all decks must have a metallic stuffing tube lined with hard rubber; in case of deck tubes, they shall be boxed near deck to prevent mechanical injury. When passing through beams and non-water-tight bulkheads must be bushed with hard rubber tubing one-eighth of an inch in thickness. For conduit work the wires must have an approved insulating covering, and for unlined conduits must have an additional second outer fibrous covering at least onethirty-second of an inch in thickness, and sufficiently tenacious to withstand the abrasion of being hauled through the metal conduit; wires must not be drawn into the conduits until the mechanical work on them is finished and the same in place.

Portable conductors must be made of two stranded conductors, each having a carrying capacity equivalent to not less than No. 14 B. & S. wire, and each covered with an approved insulation and covering. Where not exposed to moisture or severe mechanical injury, each stranded conductor must have a solid insulation at least one-thirty-second of an inch in thickness, and must show an insulation resistance between conductors, and between either conductor and the ground, of at least one megohm per mile after one week's submersion in water at seventy degrees Fahrenheit and after three minutes' electrification, with 500 volts, and be

protected by a slow-burning, tough-braided outer covering. Where exposed to moisture and mechanical injury-as for use on decks, holds and fire rooms-each stranded conductor shall have a solid insulation, to be approved, of at least one-thirty-second of an inch in thickness and protected by a tough braid. The two conductors shall then be stranded together, using a jute filling. The whole shall then be covered with a layer of flax, either woven or braided, at least one thirty-second of an inch in thickness, and treated with a non-inflammable, waterproof compound. After one week's submersion in water at seventy degrees Fahrenheit, at 550 volts and a three minutes' electrification, must show an insulation between the two conductors, or between either conductor and the ground, of one megohm per mile.

Bell or other wires shall never be run in the same duct with lighting or power wires.

When greater conducting area than that of 19 B. & S. G. is required, the conductor shall be stranded in a series of 7, 19, 37, 61, 91 or 127 wires, as may be required; the strand consisting of one central wire, the remainder laid around it concentrically, each layer to be twisted in the opposite direction from the preceding.

Switchboards must be made of non-combustible, non-absorptive insulating material, such as slate or marble, must be kept free from moisture, be located so as to be accessible from all sides, have a main switch, main cut-out and ammeter for each generator, also a voltmeter and ground detector, and a cut-out and switch for each side of each circuit leading from the board.

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Resistance boxes must be made of non-combustible material in such a way as to allow sufficient ventilation for the uses to which they are put, and should preferably be located on the switchboard, but when not on the board, must be mounted on non-inflammable, non-absorptive insulating material.

Switches must have non-combustible, non-absorptive insulating bases, must be double-pole when circuit which they control supplies more than six sixteen-candle-power lamps or their equivalent, and when exposed to dampness they must be enclosed in a water-tight case. When located on the switchboard they must be of the knife pattern. Each freight compartment must be separately controlled by a switch.

Cut-outs with proper non-combustible, non-absorptive bases must be placed at every point where a change is made in the size of the wire (unless the cut-out in the larger wire will protect the smaller wire), and in such places as upper decks, holds, cargo spaces and fire rooms a water-tight and fireproof cut-out may be used, connecting directly to mains when such cut-outs supply circuits requiring not more than 600 watts energy; when placed anywhere except on switchboards and certain places, as cargo spaces, holds, fire rooms, etc., where it is impossible to run from center of distribution, they shall be in a cabinet lined with fire resisting material. A single-pole covered cut-out may be placed in the moulding when same contains conductor supplying circuits requiring not more than 220 watts energy. Except for motors, searchlights and diving lamps shall be so placed that no group of lamps, requiring a current of more than six amperes, shall ultimately dependent upon one cut-out.

Fixtures shall be mounted on blocks made from well-seasoned lumber treated with two coats of white lead or shellac, and shali be wired with same grade of insulation as portable conductors which are not exposed to moisture or mechanical injury. Ceiling fixtures over 2 feet in length must be provided with stay chains.