Abstract :
Before beginning this discussion I want to say one word about Mr. Waterman´s comment. I did not think I was to be misunderstood in stating that the conditions of the Valtellina line favored the three-phase system. These conditions would possibly be considered very unfavorable in Europe, but in this country they would certainly be considered favorable, for the curves there are not nearly so severe and the grades are not nearly so numerous as here. This brings me naturally to Mr. de Muralt´s paper, and I want to state that it must not be forgotten that in all discussions of the substitution of one motive power for another, it must be borne in mind that the existing service is not merely replaced by something that does as well, but by something that does much more than that. Who is there that is operating electric street cars by electricity that is satisfied, or would be satisfied, with the same service from electricity that he once got from horses? Nobody. The advent of electric traction, bringing new possibilities, also increased the demands of the public. It increased the requirements that were prescribed for the electrical engineer by the railway line owners and managers. The difficulty is that the street railway has progressed marvellously, and this has happened because facilities for its development were furnished by electric traction. The same condition prevails where electricity is substituted for steam on steam roads. The railroad president or manager is not satisfied with the substitution of electricity unless the trains are run faster and cheaper. One of the other reasons why I mentioned the Valtellina line as being a favorable case is that the runs are longer than would be the case in most suburban lines, and that the acceleration required is not so great. I need not dilate on that subject because if the length of the run is decreased and the acceleration increased the comparison becomes much less favorable.
