them again after they are in place but before they are connected to the circuit. Finally each and every cir cuit should be tested after everything is complete and everything in place except the lamps. In this manner it is easy to secure proper insulation provided proper materials are used, and by making periodical tests and keeping a record of the measurements we can always tell the condition of the insulation and can readily maintain the required standard.

CHAPTER XX.

THE 1896 EDITION OF THE CODE.

Since Chapter XIX was written the code has been revised, and the revised edition, dated January 1st, 1896, has been distributed. We would suggest that those of our readers who are interested in watching the evolution of the code compare the code of 1895 with the code of 1896 section by section. Such a comparison made upon the publication of each new edition will be a great help to any one who wishes to keep in touch with the electrical inspectors. The code of 1896 differs but little from the preceding edition, and the changes consist for the most part of the addition of certain specific requirements to the general requirements of the earlier edition. In the preceding edition. the "Definitions" which explained the rules were printed as an appendix at the end of the code. In the present edition these definitions are incorporated into and made a part of the rules themselves, a change which will be a great help to those using the code in practical work and to those who wish to glance through it occasionally to find out what is required for a special kind of construction. Every one who refers to the code should have a copy of this edition. The edition of January 1st, 1896, opens with a page of "General

Suggestions." These suggestions cover the broad principles of the code to which we have endeavored to call special attention in our articles. Following are the suggestions which we believe will be readily understood and appreciated by our readers without comment on our part, but it should be noted that they show clearly how thoroughly the underwriters appreciate the fact that safety is to be secured only by intelligent design and careful and honest workmanship:

GENERAL SUGGESTIONS:-In all electric work conductors, however well insulated, should always be treated as bare, to the end that under no conditions, existing or likely to exist, can a grounding 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, tapping 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 the work should, if possible, be started from a center of distribution, and the switches and cut-outs, controlling and connected with the several branches, be grouped together in a safe and easily accessible place, where they can be readily got at for attention or repairs. The load should be divided as evenly as possible among the branches, and all complicated and unnecessary wiring avoided. The use of wireways 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, and in specifications for electric gas lighting to require a two-wire circuit, whether the building is to be wired for electric lighting or not, so that no part of the gas fixtures or gas piping be allowed to be used for the gas-lighting circuit.

We believe we are justified in concluding from the above " Suggestions" that what are most needed in the electric art are, first, the use of more brains in the designing of plants and systems of conductors; and, sccond, better workmanship. Better workmanship can be obtained by more thorough inspection and by establishing some standard of skill for workmen so that intelligent and careful wiremen shall be better paid, and the men who are not mechanics shall either become laborers or go into some other line of work where their carelessness will not endanger the lives and property of others. As the revised code contains no radical changes we will not review the entire text, but will simply call attention as briefly as possible to the changes that have been made. We will take these up under the various "Classes of work in the order given in the code.

"Class A, Central Stations."-Under Rule 1

erators," section "b" now reads:

"Gen

b. Must be insulated on floors or base frames, which must be kept filled to prevent absorption of moisture, and also kept clean and dry. Where frame insulation is impossible, the inspector may, in writing, permit its omission, in which case the frame must be permanently and effectively grounded.

This change is made to allow and regulate the use of "direct coupled" dynamos, i. e., dynamos which are coupled direct to an engine without the use of belts or gears, the armature of the dynamo being mounted directly upon the engine shaft. An engine is always 'connected (electrically) to the earth so that it is difficult to insulate the frame of a dynamo from the earth

when the dynamo and engine are direct coupled. It is therefore considered better practice (when the voltage of the dynamo is not excessively high) to depend upon the insulation of the conductors of the dynamo and not attempt to insulate the frame or body of the dynamo from the earth. If the frame of the dynamo is effectively grounded, any defect in the insulation of the dynamo will be discovered by the ground detector or by an insulation test made upon the conductors of the system. As there are no safety devices between the conductors of a dynamo and its frame, it follows that the frame should either be thoroughly insulated or else thoroughly grounded. Direct coupled machines are now the rule rather than the exception in isolated plants, and the above rule is a formal approval of what has been common practice for two or three years.

66

Rule 6, Lightning Arresters," section "d," now reads:

d. Must be so constructed as not to maintain an arc after the discharge has passed, and must have no moving parts. It is recommended to all electric light and power companies that arresters be connected at intervals over systems in such numbers and so located as to prevent ordinary discharges entering, over the wires, buildings connected to the lines.

The clause "must have no moving parts" is inserted to shut out the use of electro-mechanical devices which are all liable to get out of order and nearly all of which nave to be re-set after one or after a few discharges in order to give protection against the next discharge. The placing of arresters at intervals over a system of outside conductors is ordinary engineering practice. It is abso