“In its power to assume alwaysthat form of energy which happensto be the most useful lies the greatimportance of electricity.” This importancehas been brought to the noticeof the public by means of the manyrecent exhibitions. Public interest hasbeen roused and there is everywhere adesire for information and a guidethrough this far reaching field for discoveryand invention. And, althoughthere are many works treating on electricityand electric light, people speciallywant a short and concise though thoroughdescription of the various schemesby which electric light is produced. Inthis thesis the object is to give a brieftreatise on one of the many schemesof producing light by electric currentsviz—The Thomson-Houston System.
In pursuing the subject of electricity,the first thing noticed is the analogyand difference between the dynamoand its older and more powerful rivalthe steam engine. The resemblances are,First as in the development of the steamengine, but few of the improvements andinventions in electrical machines weremade by mathematical leaders. Wattran across the idea of the seperatecondenser while repairing the Newcomenmodel and applied theexpansion of steam to the steamengine by a mechanical accidentrather than by his own ingenuity,and so we find the first designersof the dynamo were mechanics ratherthan philosophers. Secondly thetendency to disregard old methodsand instruments because of newdiscoveries and inventions has, as inthe steam engine, hindered theadvancement in electrical science.As an example it has become customaryto regard frictional and staticalelectric machines, for practicalpurposes, as obsolete, but recent discoveriesseem to hint that they mayyet be utilized. Lately Prof. Dodge hasshown that dust and vapor whirlingin the air may be settled by adischarge of electricity consisting ofa continuous series of electric sparks.This has been utilized to clear the atmospherein lead smelting worksfrom the fumes of volatized leadand with its application comes theinvention of Wimhurst which produceswith a minimum of mechanicallabor a continuous series of electricsparks and works admirably.
The differences between the engine’sand dynamo’s developement are:First the marvelously rapid developementof the dynamo as compared withthat of the steam engine. Since 1867when the term “dynamo electric machinery”even to scientific men hadbut little signification, the dynamohas been brought to a very highdegree of perfection. Secondly, thedevelopment of the dynamo hasreached a much higher degree ofperfection than that of the steamengine. Among the best steam enginestwenty per cent effeciency isconsidered as very good while a gooddynamo gives out in the form ofelectricity, ninety per cent of themechanical energy put in it. Butthe class of people who improved andmade the steam engine what it iswere as well educated in one senseas were the men who brought outthe dynamo. While it is true that inWatt’s time the knowledge concerningsteam was very meagre, yet thepractical men who made the dynamo,did it by themselves as nearlyall the teachers of electricity knewnothing except what may be calledelectrical tricks. As has been said[1]“The teachers and writers of textbooks,p