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16 additional paper, as they will be ap- pended to the paper. The President: The society is in re- ceipt of some remarks on this paper by George H.. Barrus, which I will ask the secretary to read. REMARKS BY MR, BARRUS. © The secretary then read the following: I am very glad to see the Massachu- setts Institute of Technology advertised before this society, for I am a "tech" man myself, and I feel that its activities are worthy of publicity, J am = sorry, however, that it has been' brought into notice through the medium of such a test, for I wish to assure the members that, in my belief, the institute work, apart from this example, is of a far higher class than that which forms the basis of the paper before us. The paper appeals to me _ personally because I have been conducting steam engineering tests all through my profes- sional life--a period of 33 years. My own work, it is true, has been largely confined to boilers and engines on land; at the same time, I have had a fair amount of experience in steamship tests. It may not be out of place to mention, in passing, that the distingiushed profes- sor, who is the leading author of the paper, when a student at Technology in 1877, was one of my pupils in the in-~ stitute's steam engineering laboratory at the time I was conducting the Dixwell experiments on superheated steam. I speak disparagingly of the paper be-: cause there are a number of things about the test which cannot be endorsed. I will endeavor to call brief attention to them. %- 1. de not endorse the methad. of determining the coal consumption by counting the number of buckets of coal dumped, guessing at the weight of most of them, and guessing at the amount of coal on the floor not fired. No code of rules for conducting boiler tests or en- gine tests ever sanctioned guess work of this kind. I presume it was an easy way to make the determination, but the easiness of this method is no excuse for discarding all the well-known re- quirements for insuring reliability in the determination of the most important ele- ment in the performance of a steam plant. 2. It is evident from the remarks of the paper that no allowance was made for the different conditions of the fires at the start and finish, which the report says might have been considerable, and I judge that no observations of their con- dition were made. I do not endorse any boiler test which does not take into ac- count these important conditions. Fur- thermore, no coal test is reliable unless started and stopped in such a way that "THE Marine REVIEW the condition of the fires can be properly estimated, and a proper allowance made for any difference. In the absence of information on this point, I regard the determination of the coal fired on this test as no indication whatever of the amount of coal actually consumed. The chances are that at the beginning of the run the furnaces were well stocked with clean coal, while at the end of: the run they were probubly filled with a mixture of coal and ashes; and the difference in the amount of coal represents a certain quantity which was actually burned but not included in the weight of coal charged to the test. In other words, the weight of coal actually burned was probably much greater than that fired and reported in the table of results. 3. I do not endorse the method fol- lowed in determining the correctness of the water meter. This was left to the manufacturers of the meter, who cali- brated it some time before the test, pre- sumably at the factory. A meter ought to be calibrated in place under the pre- cise conditions of use, and it ought to be done by the persons who are conduct- ing the evaporative test. I have used a great many hot water meters in' test work, and I have always found this to be one of the essentials of reliability. 4. I do not endorse the figure 11.2 given in the report as. the equivalent evaporation from and at 212 degrees per pound of coal. This is merely a ques- tion of correct arithmetical computation from the data given. Using the figures given in the advance copy of the paper which are > Dotale coal: fired.) 3 ye eas 179,112 Ib. otal avaten: fedeoc te ak ke Oe: 2,041,710 1b. Boiler pressute: oy acini oles 137.8 lb. Ouality oT steamers ey ce, 95.9 per cent Temperature of feed water....... 203.57 my computation gives 11.53 pounds from and at 212 degrees per pound of coal instead of 11.2 pounds. 5. My principal reason for criticizing the coal and water measurements is that the evaporative result is well nigh im- possible of attainment under the condi- tions stated. In speaking upon _ this point, however, two assumptions must be made. One is that the weight of coal given is the weight uncorrected for moisture, and the other is that the coal was a fair grade of semi-bituminous, which is common in the eastern market. On these points I make the following assumptions : Percentage ot smoistire in coal.......... 3 Percentage of ash and refuse actually PUOCMCCM ie ee so eye vic ce 10 bebe Oe mer lo. or dry coals? yi... 7 14,500 Be Dy We per 1b. of combustible... 61... ., 15,300 With these assumptions, which in ev- ery case correspond to good practice, the evaporation is 11.87 potinds of water from and at 212 degrees per pound of ' factory. dry coal, and 13.19 pounds per 'pound of combustible; also, the thermal efficiency based on dry coal is 79 per cent; ang on combustible 83 per cent. Everyone familiar with boiler performance knows that such results as these are well-nigh impossible in any hand-fired boiler, whatever system of operation is em- ployed, if worked under the conditions pertaining to this test. I have person- ally conducted hundreds of boiler tests, but I have never obtained so high a per- centage of efficiency as 83 per cent. 6. I do not endorse the incomplete- ness of the work which characterizes this test. So far as the report gives any intimation there was no determination of the temperature of the flue gases, the temperature of the air supplied to the furnaces from the Howden system, the force of blast in the ash pits, the force of draft in the furnace, the composition of the flue gases as determined by gas analysis, the moisture in the coal, or the kind of coal, afl ot which' are' quite as important to the engineer as the meager statement of the evaporation per pound of coal. There is also a notable lack of information regarding the boiler dimensions, and the dimensions of the ' Howden apparatus, to say nothing of de- tails in regard to the Parsons turbines and auxiliaries. It has always seemed to me that the results of tests are of little value to engineers unless accompanied by full 'information in regard to the plant from which they are taken. 7. Finally, I do not endorse the meth- od of determining the shaft horsepower. Leaving out of ccnsideration the break- down which occurred, and which threw out the indications of one shaft meter; the horsepower is based on an assumed tortional modulus of elasticity, An as- sumption of this kind is far from satis- The only reliable figure is one which . is actually determined upon the individual shafts in use. As the paper States that .this was not done there is doubt as to the reliability of the shaft horse power given. 8. I regret to make these adverse crit- icisms of a paper which has been passed upon by the officers of the society, but I for one desire to see data in the pub- lished transactions which is not only in- teresting, but absolutely reliable, and Open to, no qttiestion; If itis not thus reliable, it should be excluded from the transactions. The President: I hand the secretary some comments on this paper by Clinton H. Crane, which I desire the secretary to read, The secretary read the following: PAPER BY CLINTON H. CRANE. I have read Prof. Peabody's paper on the "Coal and Water Tests of the