  Thomson Houston Dynamo Operates. The Sawyer-Man Incandescent Lamps. Experiments with Three Light T-H. Dynamo No. 79 “In its power to assume always that form of energy which happens to be the most useful lies the great importance of electricity.” This importance has been brought to the notice of the public by means of the many recent exhibitions. Public interest has been roused and there is everywhere a desire for information and a guide through this far reaching field for discovery and invention. And, although there are many works treating on electricity and electric light, people specially want a short and concise though thorough description of the various schemes by which electric light is produced. In this thesis the object is to give a brief treatise on one of the many schemes of producing light by electric currents viz—The Thomson-Houston System. In pursuing the subject of electricity, the first thing noticed is the analogy and difference between the dynamo and its older and more powerful rival the steam engine. The resemblances are, First as in the development of the steam engine, but few of the improvements and inventions in electrical machines were made by mathematical leaders. Watt ran across the idea of the seperate condenser while repairing the Newcomen model and applied the expansion of steam to the steam engine by a mechanical accident rather than by his own ingenuity, and so we find the first designers of the dynamo were mechanics rather than philosophers. Secondly the tendency to disregard old methods and instruments because of new discoveries and inventions has, as in the steam engine, hindered the advancement in electrical science. As an example it has become customary to regard frictional and statical electric machines, for practical purposes, as obsolete, but recent discoveries seem to hint that they may yet be utilized. Lately Prof. Dodge has shown that dust and vapor whirling in the air may be settled by a discharge of electricity consisting of a continuous series of electric sparks. This has been utilized to clear the atmosphere in lead smelting works from the fumes of volatized lead and with its application comes the invention of Wimhurst which produces with a minimum of mechanical labor a continuous series of electric sparks and works admirably. The differences between the engine’s and dynamo’s developement are: First the marvelously rapid developement of the dynamo as compared with that of the steam engine. Since 1867 when the term “dynamo electric machinery” even to scientific men had but little signification, the dynamo has been brought to a very high degree of perfection. Secondly, the development of the dynamo has reached a much higher degree of perfection than that of the steam engine. Among the best steam engines twenty per cent effeciency is considered as very good while a good dynamo gives out in the form of electricity, ninety per cent of the mechanical energy put in it. But the class of people who improved and made the steam engine what it is were as well educated in one sense as were the men who brought out the dynamo. While it is true that in Watt’s time the knowledge concerning steam was very meagre, yet the practical men who made the dynamo, did it by themselves as nearly all the teachers of electricity knew nothing except what may be called electrical tricks. As has been said[1] “The teachers and writers of textbooks, practically did not know that there was anything in common between the electricity from a rubbed glass machine and voltaic electricity, or to be brief, that there was a science of electricity as distinguished from mere natural history.” In fact as late as 1870 there were really no textbooks on electricity. Even now electrical knowledge is so meagre as to warrant the same writer’s expression, “We can not imagine a mechanical engineer mistaking a few inches for a few miles or a grocer compounding an ounce of sugar with a carload, but this gives too truthful an idea of the vagueness that still exists.” In the distant future, electricity will be used for electric lighting only as subordinate to other uses to which it may be applied such as heating houses, taking place of stoves for cooking, being used as a substitute for the steam engine. In fact the motor is rapidly becoming of as much practical use as the electric light. The principle of the motor is just this; a certain amount of mechanical energy say thirty four horsepower per minute into the form of electric currents, which by the way gives enough current to run 45, 2000 candle power lamps, send the current and distance through suitable conductors and attach them to similar dynamo or dynamos but in such a manner that the current in the second set of dynamos flows in the reverse direction to that of the first; when, the armature of the second dynamo or dynamos will revolve and at the pulley or pulleys of the dynamos, aside from friction, will be given out 95% of the thirty-four horsepower, the loss being due to the resistance of the conductors. Now in practice a motor is placed on the arc light circuit the same as a lamp, for energy less than twelve horsepower. It does not affect the lights and is a clean, neat way of obtaining energy. But however true the foregoing may be, the greatest present use of electricity is to start and maintain light. There are several so-called systems, embracing dynamos, lamps, regulators, etc, from which I select the Thomson-Houston as the one for the purpose of describing for several reasons, first, it is at least as good as the average system of which there is a mushroom growth; second, valuble information was kindly offered by the parent Company; third, a good plant is near to which free acess was given, and fourth, we have at the Mechanical Hall of this University, a dynamo, loaned by the parent Company, which affords information without any inconvenience. As each part of the system comes up to be described a little of its history will be given. As the first part of a system necessary to be produced is the current generator we will first describe |
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