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but I have myself supervised certain tests on the indicator and others asso- ciated with me hiave carried the work further, and I believe that we appreci- ate the errors' of the indicator more vividly than most people do. Any one who expects to get a precision of 2 per cent with an indicator shows very great optimism, and errors. greater than that are not to be looked upon as unusual in any place. Some statements were referred to us by Mr. Taylor. We 'have not the data upon which we can report the displacement at the present time. We should tbe very glad to append that to the paper, or to present it at some future time, if we can get the infor- mation upon which it can be based. As one of the speakers remarked, the builders of apparatus, the builders of turbine steamers, show great. reti- cence in regard to giving out infor- mation of this sort. We have no criticism on their attitude. This is a matter entirely in their province. Of course, we want everything, all the information there is, the opportunity for getting all the information we de- sire, but they see their side of the proposition, and sometimes we are not able to get what. we want.: I can appreciate the other side also. The determination of the speed is asked for at the same time, and that we know, approximately, but I do not just like to quote it, as being a thing which is not included in this paper, but we regard it as a matter that we ourselves determined in a manner which was satisfactory to us. The question of the relation of in- dicated horsepower to shaft horse- power, is just now a burning question. I believe that it is a very difficult question to decide, and shall not be satisfied with any such work as that which is being done, until the con- ditions are such that one may know on a given engine what the shaft horsepower is and the indicated horse- power by methods which are as good as we can make them. It may be noted, in passing, that none of the common torsion meters can be used upon the shaft of a reciprocating en- gine. Consequently, a very easy way of getting the torsion of the shaft, and getting the shaft horsepower of reciprocating engines, is not available. I do not want to dwell on this, but I will mention certain work which has been done at the institute to try to discover that, but it was altogether experimental and we have not been able to bring it to a stage in which we were Satisfied we were any more 'TRAE Marine REVIEW than on 'the right path. There are some things that might be interesting if presented, but I do not think they are of value. One then is obliged to revert to the estimates, let us say, of the rela- tion of the shaft horsepower to the indicated horsepower of reciprocating engines, estimates which I feel archi- tects have been forced to make for many years, and in which. they are almost always glad to quote someone else, and you find the relation is vari- ously quoted from 85 to 90 per cent. From what 'little experience and ob- servation I have been fable to secure on this matter, I am inclined to be- lieve that for reciprocating engines the ratio is nearer 90 per cent than 85 per cent, but I shall be glad to withdraw this opinion if I could get any real evidence. As to the turbine, the power applied by the steam to the turbine which corresponds with the indicated horsepower, that is prob- ably separated by a smaller interval. The friction of the turbine must be less than the friction of the reciprocat- ing engine, especially since with the Parsons turbine tthere is no thrust block, or rather very small pressure. on the thrust block, and therefore only small friction at that place. The other items, if the chair will admit, I will ask Prof, Leland to answer to. Prof. Walter S. Leland: I know that Mr. Barrus doubts our figure on equivalent evaporation. It would seem to me, that when these figures have been computed by members of the faculty of a reputable institution of learning, if any one cares to doubt them, it is up to him to present his figures. You can get about 11.53, if you use the ordinary weight of cold water, but if the specific heat of the water is taken into account, I am un- able to get that figure. If Mr. Barrus would like to present his figures, so that they could be looked over, I think that would be the proper thing to do, otherwise I think the burden of proof is on him, especially as he does not say what he uses for the weight of a cubic foot of water at the temperature of the water passing through the meter. In regard to the calibration of this particular meter, I would say it was calibrated by the Hersey Co. before the test and after- the test. Due to some changes in our own laboratory at the Institute of Technology, it was impossible to calibrate it after the test. The difference between the two results obtained was tabout one-quarter of 1 per cent, between the curves ob- tained before the test and after the in 12 'hours. 17 test. The meter which was used had been used by us previously, and we tested it after the test and the Her- sey Co. tested it before the. test, and the difference in the result was less than one-half of 1 per cent, and it does not seem very probable that that because the meter was in the ves- sel instead of sitting on the laboratory floor, in exactly the same conditions, where we tested for the water at the same temperature, that just because the meter was in the vessel it could behave radically different from what it did when it was in the laboratory. I would further add that the Institute of Technology has had considerable experience with the Hersey hot water meters, both large and small, and I was going to say that we have nearly tested them to destruction. They have been thoroughly tested, and we come near knowing if the results shown are far off. When a person suggests measuring the amount of water in tests of this sort in barrels, or in any other measure, he over- looks the fact that 2,041,710 1b. of water was spread through the boiler The obtaining of the temperature of flue gases, etc., is some- thing, of course, that is not possible under the ordinary conditions of run- ning. Mr. Crane refers to the meters he used as giving results that were not satisfactory. It was tested before the company before he used it, and he ran the water through the meter and measured it in barrels, but got a dif- ferent result. I have nothing to say in regard tto that, except that Mr. Crane neglects to state whether the had an ordinary cold water meter or a hot water meter, especially designed for the temperature of the water passing through it. The difference is very radical. A cold water meter, used for measuring water at a tem- perature of 110° will not give results anywhere near correctly. derrun every time. All we have to say is that the meter was tested be- fore and after, and it gave substan- tially the same results, an error with- in less than one-half of 1 per cent. He says that the steam consumption was 169 1b., and he probably over- looks the fact that that is for all pur- poses. We report the steam consump- tion for the turbines at 14.76 lb. per shaft H. P. per hour, and we note the fact that it contains 4 per cent prim- ing. If that is figured out on the basis of indicated horsepower, assum- ing perhaps the ordinary factor of 85 per cent, which would give approxi- mately 12.5 lb, and nobody need be ' It will un- .