The meeting of the American Association, again, was not distinguished by any particular electrical paper, or any new electrical subject. The main subject that was brought before us was the peculiar effect called "Hall's effect," that Professor Hall, now of Harvard College, and then assistant to Professor Rowland, discovered in the powerful field of a magnet when a current was passed through a conductor; and a description of that effect (which he at one time thought was an indication that electricity was something separate from matter) formed the subject of two debates that lasted for nearly the whole of two days. I am bound to say that in that prolonged discussion the members of this Society held their own. I see two very prominent members present who spoke on most of the electrical subjects dealt with - Professor G. Forbes, who knows what he says and says what he knows, and Professor Silvanus Thompson, who held his own under very trying circumstances.
At the same time that this meeting of the American Association was being held at Philadelphia, where we were treated with marvelous hospitality, - excursions, soirées, dinners, parties, etc., etc. - and as though it were not quite sufficient to bring over humble Britishers from this side of the Atlantic to suffer the intense heat at one meeting of the Association, they held at the same time an Electrical Conference. There was a conference of electricians appointed by the United States Government, that was chiefly distinguished on the part of the American Government by selecting those who were not electricians. But many attended the Electrical Conference who stand high as electricians, one especially, who, though perhaps from want of experience he did not shine very brilliantly as a chairman, certainly stands as one of the ablest electricians of the day - I mean Professor Rowland. The Conference was held under Professor Rowland's presidency, and nearly all the well-known professors of the United States attended.
The Conference was established by the United States Government to take into consideration the results and conclusions arrived at by the Congress of 1884, held in Paris. The Paris Congress decided upon adopting certain units of resistance of electromotive force, of current, and of quantity, and they determined the particular length of a column of mercury that should represent the ohm - a column of mercury 106 centimeters long and of one square millimeter in section. It was necessary that the United States should join this Conference, so a commission was appointed to consider the whole matter. All these units were brought before them, as well as the other conclusions of the Paris Congress, such as the proper mode of recording earth currents and atmospheric electricity. The Paris units were adopted in face of the fact that the length determined upon at Paris was not the length that Professor Rowland himself had found as that which should represent the ohm. It differed by about 0.2, as near as I can remember; but it was thought so necessary that uniformity and unanimity should exist all over the world in the adoption of a proper unit, that all differences were laid aside, and the Americans agreed to comply with the resolutions of the Paris Congress.
There were two units that I had the temerity to bring forward, first, at the British Association, and secondly, before the Electrical Conference. It will be remembered, that at the meeting of the British Association at Southampton in 1882, the late Sir W. Siemens proposed that the unit of power should be the watt, and that the watt, which was derived from the C.G.S. system of absolute units, should in future, among electricians, be the unit of power. This was accepted by the British Association at Montreal, and it was also accepted by the American Electrical Conference at Philadelphia. But I also, at Montreal, suggested that as the watt was the unit of power, so we ought to make some multiple of that unit the higher unit of power, comparable to that which is now represented by the well-known term "horsepower." Horsepower, unfortunately, does not form itself directly into the C.G.S. system. The term horsepower is a meaningless quantity; it is not a horsepower at all. It was established by the great Watt, who determined that the average power exerted by a horse was equal to about 22,000 foot pounds raised per minute; but this was thought by him to be too little, so he increased it by 50 per cent., and so arrived at what is the present horsepower, 33,000 foot pounds raised per minute.
Foot pounds bear no relation to our C.G.S. system of units, and it is most desirable that we should have some unit of power, somewhere about the horsepower, to enable us to convert at once watts into horsepower. For that purpose I proposed that 1,000 watts, or the kilowatt, should replace what is now called the horsepower, and suggested it for the consideration of engineers. It has been received with a great deal of consideration by those who understand the subject, and a considerable amount of ridicule by those who do not. It is rather a remarkable thing that, as a rule, one will always find ridicule and ignorance running side by side; and it is an almost invariable fact that when a new proposition is brought forward, it is laughed at. I am always very glad to see that, because it always succeeds in drawing attention to the matter. I remember a friend of mine, who had written a book, being in great glee because it was severely criticised by the Athenaeum, a fact which drew public attention to the book, and caused it to make a great stir.
So when I proposed that the horsepower should be increased by 33 per cent., and made equivalent to 1,000 watts, I was not at all sorry to find that I had incurred the displeasure of the leader writers in nearly all our scientific papers, and I was quite sure that the attention of those who would not perhaps have thought of it would thereby be drawn to the matter. Some people object to the use of a name, this name "watt." When you have fresh ideas, you must have fresh words to express those ideas. The watt was a new unit, it must be called by some name, otherwise it could scarcely be conveyed to our minds. The foot, the gallon, the yard, were all new names once; and how do we know that they were not derived from some "John Foot," "William Gallon," or "Jack Yard," or some man whose name was connected with the measure when introduced? The poet says:
"Some mute, inglorious Milton here may rest - Some Cromwell, guiltless of his country's blood:"
so in these names some forgotten physicist or mute engineer may be buried. At any rate, we cannot do without names. The ohm, the ampere, the volt, are merely words that express ideas that we all understand; and so does the watt, and so will the 1,000 watts when you come to think over the matter as much as some of us have done.
At this Conference several other subjects were brought up which attracted a good deal of attention. Professor Rowland brought forward a paper on the theory of dynamos that certainly startled a good many of us; and it led to a discussion that is admirably reported in our scientific papers. I think that the discussion evolved by Professor Rowland's paper on the theory of dynamos deserves the study of every electrician; it brought very strongly into prominence one or two English gentlemen who were present. Professor Fitzgerald, of Dublin, spoke with a considerable amount of power, and showed a mastery of the subject that was pleasant not only to his friends, but must have been gratifying to the Americans who heard him. On this particular subject of dynamos it was truly wonderful how the doctors disagreed. Two could not be found who held the same views on the theory and construction of the dynamo, and that shows that we still have a great deal to learn about the dynamo, and that the true principle of construction of it has yet to be brought out.
It is a very curious thing, and I thought about it at the time, that when you consider the dynamos in use, you see how very little has been done to perfect the direct working dynamo in England. Although the principle of the dynamo originated with Faraday, yet all the early machines, Pacinotti, Gramme. Hefner von Alteneck, Shuckert, Brush, Edison, and several others who have improved the direct action machine, have not been found in England. But when we deal with alternate-current machines, then we find the Wilde, Ferranti, and various others; so that the tendency in England has been very much to improve and work upon the alternate-current machines. In other countries it is exactly the reverse; in fact, in America I never saw one single alternate-current machine. When Professor Forbes wanted an alternate-current machine to illustrate a lecture that he gave, it was with the greatest difficulty that one could be found, and, in fact, it was put together specially for him.
The other subjects brought before this Conference were Earth Currents, Atmospheric Electricity, Accumulators or Secondary Batteries, and Telephones. There was an extremely able paper brought forward by Mr. T.D. Lockwood, the electrician of the American Bell Telephone Company, on Telephones, and the disturbances that influence their working. When that paper is published, it will well be worth your careful examination.
Papers were also read on the Transmission of Energy, and there were papers on many other subjects.
So much for the Electrical Conference.
Now, the Americans at the present moment are suffering from a mania which we, happily, have passed through, that is, the mania of exhibitions.
While we were at Philadelphia, there was an exceedingly interesting exhibition held. I do not intend to say much about that exhibition, for the simple reason that Professor G. Forbes has promised, during the forthcoming session, to give us a paper describing what he saw there, and his studies at Philadelphia; and I am quite sure that it will be a paper worthy of him, and of you. But, apart from this exhibition at Philadelphia, I could not go anywhere without finding an exhibition. There was one at Chicago, another at St. Louis, another at Boston; everybody was talking about one at Louisville, where I did not go; and there were rumors of great preparations for the "largest exhibition the world has ever seen," according to their own account, at New Orleans. However, I satisfied myself with seeing the exhibition at Philadelphia, which consisted strictly of American goods, and was not of the international nature general to such exhibitions. But it was a fine exhibition, and one that no other single nation could bring together.