The "National Electrical Code," as it is here presented, is the result of the united efforts of the various insurance, electrical, architectural and allied interests which have, through the National Conference on Standard Electrical Rules, composed of delegates from various national associations, unanimously voted to recommend it to their respective associations for approval or adoption. The following is a list of the associations represented in the Conference, all of which have approved of the Code :—

American Institute of Architects. American Institute of Electrical Engineers. American Society of Mechanical Engineers. American Street Railway Association. Associated Factory Mutual Fire Insurance Companies. National Association of Fire Engineers. National Board of Fire Underwriters. National Electric Light Association. National Electrical Contractors' Association Underwriters' National Electric Association.

GENERAL PLAN

GOVERNING THE ARRANGEMENT OF RULES.

CLASS A. — STATIONS AND DYNAMO ROOMS. Includes Central Stations; Dynamo, Motor, and Storage-Battery Rooms; Transformer Substations; Etc. Rules 1 to 11.

CLASS B. — OUTSIDE WORK, all systems and voltages. Rules 12 to 13 A.

CLASS C. — INSIDE WORK :— General Rules, all systems and voltages. Rules 14 to 17. Constant-Current Systems. Rules 18 to 20. Constant-Potential Systems :— General Rules, all voltages. Rules 21 to 23. Low-Potential Systems, 550 volts or less. Rules 24 to 34. High-Potential Systems, 550 to 3500 volts. Rules 35 to 37. Extra-High-Potential Systems, over 3500 volts. Rules 38 and 39.

CLASS D.—FITTINGS, MATERIALS, AND DETAILS OF CONSTRUCTION, all systems and voltages. Rules 40 to 63.

CLASS E.—MISCELLANEOUS. Rules 64 to 67.

CLASS F.—MARINE WORK. Rules 68 to 83.

GENERAL SUGGESTIONS.

In all electric work, conductors, however well insulated, should always be treated as if they were bare, to the end that under no conditions, existing or likely to exist, can a ground or short-circuit occur, and so that all leakage from conductor to conductor, or between conductor and ground, may be reduced to the minimum. In all wiring, special attention must be paid to the mechanical execution of the work. Careful and neat running, connecting, soldering, taping of conductors, and securing and attaching of fittings, are especially conducive to security and efficiency, and will be strongly insisted on. In laying out an installation, except for constant-current systems, every reasonable effort should be made to secure distribution centers located in easily accessible places, at which points the cut-outs and switches controlling the several branch circuits can be grouped for convenience and safety of operation. The load should be divided as evenly as possible among the branches, and all complicated and unnecessary wiring avoided. The use of wire-ways for rendering concealed wiring permanently accessible is most heartily endorsed and recommended; and this method of accessible concealed construction is advised for general use. Architects are urged, when drawing plans and specifications, to make provision for the channeling and pocketing of buildings for electric light or power wires.