celain or glass insulators, or hard rubber hooks. They should also be provided with an approved insulation covering.

19. When wires pass through walls, floors, partitions, etc., in-doors, glass insulators, or an extra covering of hard rubber, should be used. Wires must never be left

exposed to disturbance or mechanical injury.

ARC LAMPS.

20. The frames and other exposed parts of arc lamps must be carefully insulated from the circuit.

21. Each lamp must be provided with a proper hand switch, and also with an automatic switch that will shunt the current around the carbons should they fail to feed properly.

22. Stops of some kind must be provided to prevent the carbons from falling out in case their clamps fail to hold them; and these stops must always be in place when the lamp is burning.

23. For inside use, the light must be surrounded by a globe resting in a tight stand, so that no particles of melted copper or heated carbon can escape. When inflammable material is near or under the lamp, the globe must be protected by a wire netting. Unless a very high globe, which closes in as far as possible at the top, is used, it must be provided with some protector or spark arrester, reaching to a safe distance above the light. Broken or cracked globes must be replaced by perfect ones immediately. (By inflammable material is meant such as dry goods, clothing, millinery and the like in stores; flyings or goods in fabric factories; shavings and saw-dust in woodworking shops, or any other substance that can be readily ignited by droppings or flyings from the lamp.)

24.

Electrical connection between the conducting wires and lamps must be made through a suitable "hangerboard" and rods on which the lamp is hung.

INCANDESCENT LAMPS ON ARC-LIGHT CIRCUITS.

25. The rules for running wires for arc lamps apply also to incandescent lamps run in series.

26. These must be provided with a proper hand switch, and also with an approved automatic device which will shunt the circuit around the carbon filament should it break. No electro-magnet device will be accepted for this purpose.

27. Any method of distributing current to incandescent lamps on arc-light circuits, other than as above provided for, must receive the approval of this Exchange before being put into use.

28.

DYNAMOS AND MOTORS.

They must be located in dry places, not exposed to the flyings of combustible material, and must be insulated upon dry wood, filled to prevent absorption of moisture. They must be kept thoroughly clean and dry. They must be provided with a reliable automatic regulating device, or a competent person must be in attendance near the machine whenever it is in operation. In wiring for motive power, the same precautions should be taken as with a current of the same volume and potential for lighting.

29. The wires leading to motors should be separated at least twelve inches from each other, and must be provided with an approved cut-out switch at the point where they enter the building. The same precautions must be observed in entering the building that are required for lighting circuits.

30.

TESTING.

All circuits should be tested at least twice a day with a suitable magneto, or other approved device, in order to discover any escapes to ground that may exist. One test should be made in the morning, and another in ample time before starting, to remove any defect should it be found to exist. The rules for testing should be observed in any separate or isolated plant the same as in central stations.

31. The New England Insurance Exchange reserves the right at any time to add to, change, or modify these rules, and to enforce such modifications, changes, etc., as it shall deem necessary for safety; and it will use all

reasonable efforts to promptly notify all electric light companies of any change.

32. The signing of these rules by an electric light company, or persons controlling electric lights, shall be considered a guaranty on their part that they will have the testing performed on their circuits or lines as above required.

INCANDESCENT SYSTEM.

OUTSIDE WIRES.

I. All outside overhead wires must be covered with some material of high insulating power, not easily abraded, and they must be firmly secured to properly insulated and substantially built supports. All the wires must have an insulation equal to that of the conducting wires. 2 All joints must be so made that a perfectly secure and unvarying connection, fully equal to the cross-section of the conducting wire, will be secured - and they should be soldered. All joints must be securely wrapped with an approved tape.

3. Care must be taken that conducting wires are not placed in such position that it would be easy for water, or any liquid, to form cross-connection between them, and main conductors or feeders should not approach each other nearer than one foot.

4. The wires must never be allowed in contact with any substance other than air, and their proper insulating supports.

5. Conducting wires carried over or attached to buildings, must be at least seven feet above the highest point of flat roofs, and one foot above the ridge of pitch roofs. Lines constructed subsequent to the adoption of these regulations should not be run over and attached to buildings other than those in which the light or power is being, or is to be, used, but should be on separate poles, or structures, where they can be easily reached for inspection.

6. When they are in proximity to other conducting wires, or any substance likely to divert any portion of the current, dead, insulated guard-irons must be placed so as to prevent any possibility of contact in case of accident to the wires or their supports. The same precautions must be taken where sharp angles occur in the line wires, and also where any wires (telegraph, telephone, or others) could possibly, owing to their position, come in contact with the electric light wires.

7.

Wires from main circuit to main cut-out inside of buildings, must be separated by a distance of not less than six inches, for currents having an electro-motive force of 250 volts or less, and this distance must be increased for currents of higher potential.

8. They must also be rigidly and neatly run, and must be supported by glass or porcelain insulators, or by rubber hooks. Rubber hooks must be of an approved pattern; i. e., with the rubber insulation free from flaws, and projecting over the hook in cup form.

9. Service blocks must be protected by at least two coats of water-proof paint over their entire surface; and when used to support rubber hooks, must have at least one inch of wood between the inner end of the hook and the back of the block.

IO. For entering buildings, wires of extra heavy and durable water-proof insulation, protected by an outside covering not easily abraded, must be used from the terminal insulator outside, to the main cut-out inside of the building. They must loop down, so that water may drip off without entering the building, and the holes through which they enter should, where possible, slant upward. If an approved glass insulator for bushing the holes is used the extra heavy insulation will not be required.

II. Service wires must come in contact with nothing save air, and their insulating supports, except in unavoidable cases, when a wire with an extra heavy insulation, suitable for the purpose, must be used.

12. The use of porcelain knobs as insulators, except in perfectly dry places, or for the support of a specially

insulated wire, will not be accepted, unless of some approved shape.

UNDERGROUND SERVICE.

13. Where underground service conductors, enclosed in a metal tube, enter a building, special care must be taken at the point where the conductors leave the tube, and thence to the main cut-out, to protect them in such a manner that they cannot come in contact with each other, nor with the tube, nor be acted upon by falling moisture, nor disturbed by anything being moved against them, etc.

14. This service must not end in any place where it would be unsafe or undesirable to place a cut-out, but should be continued by means of specially insulated conductors (and a space of ten inches should be maintained between them) to a suitable location.

INSIDE WIRING.

15. Copper wire used for incandescent lighting must be procured for manufacturers whose products have been found, by reliable tests, to be at least 95 per cent conductivity. Samples of wire to be used, or in actual use, must be submitted to this Exchange, for tests of conductivity, at any time when required. Samples of wire must also be submitted for tests of insulation, at any time when required.

For inside work, no wires smaller than No. 16 "B. & S." or No. 10" B. W. G." will be approved.

16. Permission will not be granted for the use of the lights unless the wire comes fully up to the standard of conductivity, no matter how well the wiring may be done.

17. All parties, firms or corporations proposing to do construction work or wiring, either outside or inside, must fully satisfy this Exchange of their ability to do the work in a safe and acceptable manner.

18. Before using any new form of insulation, the approval of this Exchange for its use under the proposed circumstances must be secured.

19. The use of lead-covered wire, or wire, the covering of which contains paraffine, is prohibited.