1888.
INTRODUCTION.
In the following pages it is my intention to give engineers on board ship, who may be put in charge of electric lighting machinery without having any electrical knowledge, some idea of the manner in which electricity is produced by mechanical means; how it is converted into light; what precautions must be used to keep the plant in order, and what to do in the event of difficulties arising. I do not therefore aim at producing a literary work, but shall try and explain everything in the plainest language possible.
CONTENTS.
| [The Electric Current, and its Production byChemical Means.] |
| | PAGE |
| [Production of electric current in chemical battery]—[Current veryweak]—[Current compared to circulation of the blood]—[Strength andvolume of current]—[Pressure not sufficient without volume]—[Actionof current is instantaneous]—[Resistance to the passage of thecurrent]—[Copper the usual metal for conductors]—[Heat produced bycurrent when wire is too small] | [1] |
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| [Production of Electric Currents by Mechanical Means.] |
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| [Magneto-Electric Machines.] |
| |
| [Current produced by mechanical means]—[Alternatingcurrent]—[Magneto-electric machines]—[Shock produced by interruption ofcurrent]—[The current must be commutated]—[Description ofcommutator]—[Current, though alternating in the dynamo, iscontinuous in the circuit]—[Continuous current used for electro-plating] | [5] |
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| [Dynamo-Electric Machines.] |
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| [Current will magnetise an iron or steel bar]—[Permanentmagnet]—[Electro-magnet]—[Where the magneto and dynamo machinesdiffer]—[Armature of so-called continuous-current dynamo]—[Type ofcommutator]—[Commutator brushes]—[Current continuous in thecircuit]—[Alternating-current dynamos]—[Current not commutated]—[Intense magnetic field produced]—[Simplicity of Ferranti armature]—[Largenumber of alternations of the current]—[Alternating current cannotbe used to excite an electro-magnet]—[Exciter coupled on to samespindle as dynamo]—[Power of exciter if used alone] | [9] |
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| [Electric Lamps.] |
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| [Production of electric light]—[Arc lights]—[Mechanism to regulate carbons]—[Some lamps suitable for alternating current]—[When carbons are consumed, light goes out]—[Arc lamps very complicated]—[Jablochkoff candles]—[Arc formed between the carbons]—[Candlesrequire alternating current]—[Incandescent lamps]—[Vacuum formed inlamps prevents combustion]—[Vacuum not perfect]—[Advantages ofincandescent lamps for house and ship lighting]—[Unaffected bywind, and suitable for either continuous or alternating currents] | [19] |
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| [Leads.] |
| [Leads made usually of copper wire]—[Short circuit]—[High E.M.F. for arc lights, but low for incandescent]—[Arc lights in series]—[Incandescent lamps in parallel circuit]—[E.M.F. same for one lampas for a number]—[If lamps suitable, each one turns on and offseparately]—[Safety fuses] | [24] |
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| [Ship Lighting.] |
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| [Position for dynamo]—[Dynamo to be kept clean and cool]—[Quick-speed engines]—[Slow-speed engines with belts]—[Means of keepingbelt on the pulley]—[Engine must work steadily]—[A good sensitivegovernor wanted]—[The belt must be kept tight]—[A handy belt-stretcher]—[Friction gearing]—[Switch board near dynamo]—[Leads ofdifferent colours]—[Main leads and branch leads]—[Lamps held infrosted globes]—[Switches for each lamp]—[Lamps of variouscandle-powers]—[Plan for lighting quarter-deck at times]—[Arrangement oftemporary leads]—[Leads and lamps always ready, and easily fixedup]—[Lighting of ships’ holds]—[Danger of fire with oil lamps]—[Arc lamps not suitable]—[Arrangement of leads for incandescent lamps]—[Work carried on better, and pilfering of cargo prevented]—[Holdleads disconnected while at sea]—[Installation complete]—[Lightswanted as night approaches]—[Precautions before starting dynamo]—[Lubricationmust be perfect]—[Commutators and collectors requirevery little oil]—[Position of brushes]—[Start the engine]—[Switches not turned on]—[No current except from exciter]—[Testingwork of exciter]—[Dynamos very powerful magnets]—[Look out for your watches]—[Switch on the lamps]—[Current is produced in large dynamo]—[Difference of a few lamps compensated by governor]—[Turn all lampson, and light up gradually]—[Inequality of light in differentlamps]—[Weeding out of bad lamps]—[Lamps not to be run too bright]—[No trouble with dynamo if oiling is attended to]—[Seizing]—[Oilmust be thin]—[The dynamo must be kept clean]—[Little troubles withthe lamps]—[No safety fuse]—[Effects of vibration of ship on lamps]—[What to look to if a lamp is out]—[Recapitulation]—[A current of50 volts is hardly felt]—[Incandescent lights for side lights]—[Mast-headlight]—[Arc light should never be used]—[Present mast-head light quite powerfulenough]—[On passenger steamers, side oneblaze of light, and side lights barely visible]—[Speed of dynamoconstant, but steam power used in proportion to number of lampsin use]—[No danger to life from electric current on board ship]—[Binnacle lamps.Electric light not suitable]—[Dynamo if near acompass will affect it]—[Notes] | [27] |
WRINKLES
IN
ELECTRIC LIGHTING.