Although this method gave occasionally good results, it was found very difficult to construct a thermopile which would be electrically insulated and at the same time not be insulated against heat, and this difficulty seems almost impossible to overcome at the present time.

Messrs. Barnes and Zimmerman, later Messrs. McGowan and Bentley, have used another method which has proved to be much more certain and practical in its nature. In these cases a constant current of electricity of small intensity was passed through

the metal the temperature of which it was desired to ascertain. The change in the electrical resistance due to change in temperature was shown by photographing the motion of a galvanometer mirror. The results in these cases confirm the work done by Adams, and the apparatus seems to be stable and reliable. The writer will try and present the results of these various investigations at a later meeting of the Society.

Mr. H. H. Suplee.-I think emphasis should be laid on the fact that an international system should be adopted, and that that should include not only England, but at least Germany and such other countries as would be willing to come in. I know that there is a very careful attempt now being made by the Society of

German Engineers to adopt a standard method of testing engines, and I think investigations have also been made in France, and it seems to me that if any committee is appointed for this purpose it should be international, just as the Committee on Standard Tests of Materials is international. I only offer that as a suggestion.

Mr. Francis H. Boyer.-Mr. Donkin's paper refers to the necessity of taking account of the effect of the temperature of cylinder walls in testing engines. We have had some very fine papers on cylinder condensation recently, and I would refer particularly to one by a junior member of the Society. By your permission I will use the board to make clear my point.

In using the indicator, our instruments often show the effect of this cylinder wall condensation, and in this way. We will have an expansion curve starting off at cut-off and then a jog, and the curve is completed by another running down to the terminal point. I have often asked our makers why we do not produce as good variation cards with our American instruments as we can with the German ones. Their reply comes back that it is a defect in our instrument. I hold it is not. Let us consider the problem.

At atmospheric pressure of the exhaust line we have a temperature of 212 degrees. At 80 pounds steam we have a temperature of 312 pounds per square inch. Now, as this steam has entered the cylinder and the pressure falls after cut-off, the temperature reduces in the same proportion, and the water which has been condensed upon the cylinder walls becomes revaporized to the extent of the range of temperature between 312 and whatever temperature it may come. That causes this increase in pressure.

You can take, for instance, 272 degrees at the centre here, which would represent a falling off of 40 degrees, and at this point this condensation which is on the walls of the cylinder bursts forth, due to the amount of heat which is in excess, and which passes from the heat held in the water to a vapor. Dr. Emery, if he were here, I am sure, would bear me out in this, because I think it was some twenty years ago that he was called on by the Government to give a reason why it was not possible to heat water to an intense degree and let it burst into steam, the reason being, if I am correct, because there were not the heat units in the water sufficient to throw it into a hot vapor. Members who come from Boston may know about the attempt to put a heating system through Boston by hot water under pressure, and you know the terrible failure they had. Why was it? They had water up to a pressure of 500 pounds per square inch, but there was too little energy in the heated water itself; it is in the latent heat of steam that we get so much of energy, and that heating power the hot water did not have. There was the defect. That same law holds good in our indicator tests. Now we find this phenomenon mostly in our cylinders on our rapid engines, and engines which have a great cylinder sweep. As I just said, we get hold of a good many instruments which don't show that effect, and yet some of the German instruments will show it perfectly. I cannot explain it, but I would like to call the attention of the meeting to the fact.

Mr. Bryan Donkin.*-I note with pleasure that the Council were authorized to appoint a committee to consider the question treated in these papers.†

With regard to Professor Carpenter's interesting remarks, I quite agree with him that it would be very desirable to retain the old standards of pounds of water per horse-power and boilerpower per horse-power, introducing at the same time the new and more accurate method of thermal units, as suggested.

* Author's closure, under the Rules.

The committee consisted of Messrs. Boyer, Barrus, Donkin, Jacobus, and Richmond.

IN addressing you as chief engineer of the Niagara Falls Power Company, in regard to some of the mechanical features of the power development at Niagara Falls, I desire to make a brief statement concerning the organization of the company which has accomplished the work in question. It must be understood that the development thus far has been conducted by the Cataract Construction Company, the officers and directors of which practically control the allied corporations including the Niagara Falls Power Company, and have appointed the engineering staff by which the operations of these several companies have been conducted.

With confidence in the ultimate financial success of the project, the leading capitalists interested have patiently watched the progress of the work, and some from the outset have individually taken a prominent and active part in the consideration of the technical questions involved, as viewed from the standpoint of sound business experience. At times, under the advice of its engineering staff, the Cataract Construction Company has proceeded in direct opposition to the opinions of men prominent in the scientific world, after careful study of the questions presented from a commercial as well as from an engineering standpoint, realizing, as the results have since justified, that it was necessary so to act from full conviction in a matter where there was so little established precedent to serve as a guide.

The plan of utilizing the power of Niagara Falls as proposed by the late Thomas Evershed, while Chief Engineer of the State of New York, contemplated the construction of a tunnel under the town, which tunnel was to constitute a tail-race from the

* Presented at the Niagara Falls meeting (June, 1898) of the American Society of Mechanical Engineers, and forming part of Volume XIX. of the Transactions.

turbines or water wheels of factories to be located on land above the American Rapids, in contradistinction to the plan of placing the turbines and factories at the river below the Falls, and bringing the water to them by a long canal. The Evershed plan, while presenting great advantages, not only called for a large amount of capital, but the active influence of men of broad business experience, who possessed the confidence of leading financiers in this country and abroad. Mr. William B. Rankine and Mr. Francis Lynde Stetson were induced to take the matter up, and in 1889 sought the advice and coöperation of Mr. Edward D. Adams, of New York, who subsequently was elected president of the Cataract Construction Company.

These gentlemen, while appreciating the advantages offered by the Evershed plan, looked beyond the mere project of estab lishing factories operated independently by their respective water wheels, to the possibility of generating power at a central point where it could be utilized in the immediate neighborhood, or transmitted to a distance, after the manner practised abroad, particularly in Switzerland, where several such plants were in operation.

In 1890 Mr. Adams devised a plan whereby the Cataract Construction Company could become fully informed as to the then most approved methods of developing water power, and its transmission and utilization. Early in that year I was retained by the company as consulting engineer, and at Mr. Adams's request I joined him in London, where, through my membership in the Institution of Civil Engineers and our intimacy with scientists in England and on the Continent, Mr. Adams's plan of organizing the International Niagara Falls Commission was perfected. The object of this commission was to obtain and consider plans submitted by engineers and engineering firms, for the generation of power, and the transmission of that power to Buffalo and to other accessible markets. The engineers thus invited to submit plans received compensation on account of the expense involved, and had also an opportunity to obtain certain premiums if their plans proved deserving of such recognition.

You are all probably aware, from what has already been made known on the subject, that the amount of valuable information thus obtained seems now quite limited as compared to what has since been discovered and adopted. There were,