CLASS E.-ELECTRIC RAILWAYS.

Power Stations.

All rules pertaining to arc light wires and stations shall apply (so far as practicable) to street railway stations and their conductors.

Railway Systems with Ground Return.

Electric railway systems in which the motor cars are driven by a current from a single wire, with ground or floor return circuit, are prohibited except as hereinafter provided:

1. When there is no liability of other conductors coming in contact with the trolley wire.

2. When the location of the generator is such that the ground circuit will not create a fire hazard to the property.

3. When an approved automatic circuit breaker or other device that will immediately cut off the current in case the trolley wires become grounded is introduced in each circuit as it leaves the power station. This device. must be mounted on a fireproof base, and be in full view of the attendant.

Trolley Wires.

TROLLEY WIRES-Must be:

1. No smaller than No. 0 B. & S. copper, or No. 4 B. & S. silicon bronze, and must readily stand the strain put upon them when in

use.

2. Well insulated from their supports, and in case of the side or double pole construction, the supports shall also be insulated from the poles immediately outside the trolley wire.

3. 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 in extinguishing the flames. This rule also applies to feeders.

4. Safely protected against contact with all other conductors.

Car Wiring.

All wires in cars must be run out of reach of the passengers, and shall be insulated with a waterproof insulation.

Lighting and Railway Power Wires.

Lighting and power wires must not be permitted in the same circuit with trolley wires with a ground return, except in street railway cars, car houses, and power stations. The same dynamo may be used for both purposes, provided the connection from the dynamo for each circuit shall be a double-pole switch so arranged that only one of the circuits can be in use at the same time.

CLASS F.-BATTERIES.

When current for light and power is taken from primary or secondary batteries, the

same general regulations must be observed as apply to such wires fed from dynamo generators developing the same difference of potential.

CLASS G.-MISCELLANEOUS.

1. The wiring in any building must test free from "grounds" before the current is turned on. This test may be made with a magneto bell that will ring through a resistance of 20,000 ohms, where currents of less than 250 volts are used.

2. No ground wires for lighting arresters may be attached to gas pipes within the building.

3. All conductors connecting with telephone, district messenger, burglar alarm, watch clock, electric time, and other similar instruments must, if in any portion of their length they are liable to become crossed with circuits carrying currents for light or power, be provided near the point of entrance to the building with some protective device which will operate to shunt the instruments in case. of a dangerous rise of potential, and will open the circuit and arrest an abnormal current flow. Any conductor normally forming an innocuous circuit may become a source of fire hazard if crossed with another conductor through which it may become charged with a relatively high pressure,

RULES OF THE NATIONAL BOARD OF FIRE UNDERWRITERS.

At the 24th Annual Meeting of the Board, held June 8th, 1890, the New York Board rules regulating Electric Light Installations were adopted for promulgation to members.

Amended Standard for Electric Equipments, Adopted January 15, 1890, by the New York Board of Fire Underwriters.

CONDUCTORS.

Capacity of Wires.

1. The conducting wires must be of copper, and must have a weight per running foot at least equal to that of the wire (or parallel group of wires) constituting the main circuit. of the magnetic regulator of the electric lamps (arc lamps), or of the armature of the machine employed, whichever of these is greatest.

Joints or Splices.

2. All joints in wires must be so made as to secure perfect and durable contacts, which

shall always maintain a degree of conductivity at the joint at least equal to that of the wire generally.

3. The joint must be so made as in the ordinary "telegraph splice" that it is mechanically secure against motion or displacement, and must then be further electrically connected by solder so applied as to leave no corrosive or otherwise injurious substance on the connection. After joining and soldering, the joint must be covered with insulating material in such a way as to make the insulation of the joint as good as that of the rest of the line.

4. A joint made by the process of electric welding would be the equivalent of one made as indicated above, but no joint depending upon solder for its mechanical integrity either wholly or in part will be allowed.

Wires Exterior to Buildings.

5. Outside wires must be covered with at least two coatings, one of insulating material, impervious to water, next to the wire, and the other of some substance fitted to resist abrasion or like mechanical injury, and must be firmly secured to substantial approved insulators, adequately supported. All "tye wires," or those used to secure the conductors to the "insulators," must be themselves covered with waterproof insulating and mechanically resist ant material similar to that used on the conductors themselves.