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28 MARINE REVIEW AND MARINE RECORD. [Sept. yy, "THE MILITARY IMPORTANCE OF NAVAL ENGINEERING EXPERIMENTS." REAR ADMIRAL GEORGE W. MELVILLE, U. S. N. The act making appropriations for the naval service for the fiscal year commencing July 1, 1903, contained a larger appro- priation for new construction than any act heretofore passed by a congress of the United States. This act not only provided for the construction of three first-class battleships of not more than 16,000 tons, and two first-class battleships of not more _than 13,000 tons displacement, but it likewise authorized the building of a naval engineering laboratory whose cost, including equip- ment, should not exceed $400,000. : *» The hulls and machinery of these five battleships will cost approximately $20,000,000. The armor, armament and equipment will require an additional outlay of $15,000,000; so that the actual cost of these battleships will probably be about $7,000,000 each. The annual depreciation of each of these vessels from the time they are launched, taking into consideration wear and tear as well as loss in fighting value, will be at least four per cent. of their actual cost. The expense attending the establishment of the proposed experimental station, including its operation for several years, will thus be but little more than the annual loss resulting from corrosion, mishaps, and depreciation of military appliances of two of these floating fighting machines. =, The rise of Germany as a naval and maritime power during the past thirty years has surprised the world. I believe that her battleships. for their tonnage are the best afloat, because they possess a triple screw installation of machinery, thus giving the motive power of her larger warships economical, structural, and tactical advantages over similar high-powered vessels of rival nations. Her ocean greyhounds are the largest, fleetest, and prob- ably the most economical and comfortable afloat. Strangest of all, this excellence in the construction of warships, as well as in the building of vessels for the ocean-going trade, is not the result of a progressive series of failures, either in design, construction, or of operation. The success of Germany can. be accounted for only by recog- nizing the fact that study, reflection, and research must have been expended in the preparation of plans, in the building up and the organization of the ship yards, and in laying out and carrying on the work of construction. It was the high appreciation of the value of original investigation, coupled with experimental work, that has caused Germany to advance progressively and success- fully. Patient investigation and carefully conducted experiments were required by the Berlin admiralty, for these officials be- lieved that unless such research was thoroughly conducted, the building up of any navy and its mercantile marine could be ac- complished only after discouragement and possibly disaster had been encountered. Where research had not been conducted, dis- appointment resulted from the construction of vessels which were either faulty in design, ill suited for the purpose intended, or upon which an inferior quality of work had been expended. For over a hundred years Germany, as a nation, has carried on more original research along technical lines than any other power. While it is true that both England and America have put to practical application the principles discovered by German re- search, thereby gaining commercial and maritime advantages, it has been the Teuton who has sought after principles, and thus the world is primarily indebted to this studious and thoughtful race for many of the great discoveries and inventions. . : 'Ina desultory and sporadic manner all naval powers have done some experimental work. It is because original investiga- tion is not always appreciated in its fullness by the Anglo-Saxon that, many administrative executive officers are indifferent to such research, and therefore experimental tests in Great Britain and America are not always of a continuing nature. Great Britain however, has recently been compelled to establish a national physical laboratory, because the encroachment of continental rivals threatened to interfere with her foreign markets. It can hardly be said that she has done this work in a manner that should be duplicated by us; since it has been affirmed that in this laboratory the standard measuring machines are installed in a 'basement room, the walls and ceilings of which are of rough brick, full of deep crevices in which dust can, and will, of course, collect. Better do no scientific work than not do it well, is the maxim of the German. Thirty-five years ago Engineer in Chief B. F. Isherwood, United States navy, carried on an extended and careful series of experiments in connection with the subject of screw propellers. The information secured at that time is standard authority to- day; but since then it has required persistent effort to arouse naval administrators to the importance of detailing ships and men. for securing data upon questions relating to the action of the screw propeller. The problem as to whether or not in-turning screws are det- rimental to maneuvering qualities would have been solved many years ago if the work planned by Mr. Isherwood had been con- tinued. Our increased knowledge of the theory and practice of screw propulsion since the Isherwood experiments is due, how- ever, almost: wholly to the work of Froude, conducted for the British admiralty. This is confirmatory evidence that such im- portant and difficult work can only be undertaken by official or *Read before Engineers' Club in Philadelphia. civilian experts who are able to call upon government resources for data and information. It requires government investigation to solve important problems relating to the powering of vessels since valuable and far-reaching experiments upon. this subject require the use of ships as well as the services of a large number of reliable and competent persons to collect the data requisite for the determination of absolute results. EXPERIMENTAL WORK DONE AT THE NAVAL ACADEMY, With a thorough realization of the importance and necessity of securing data upon screw-propeller, problems, the head of the steam engineering department of the United States naval acad- emy, Rear Admiral C. W. Rea, new engineer in chief of the United States navy, assisted by the instructors in his department, commenced in 1895 what promised in some respects to be an ex- tended investigation of the problem. These tests were interrupted by the demands of the Spanish-American war, since everything at the naval academy had at that time to be subordinated to hast- ening the graduation of the senior classmen. The plant consisted of a small, triple-expansion engine, turn- ing a shaft upon which was fixed a propeller submerged jin a tank of water. This tank was so arranged that the column of water driven forward or back, depending upon the direction of motion of the engine, returned on the opposite side of the tank to the propeller. Between the engine and the tank two dynamometers were placed on the shaft--a direct thrust and a rotary one. Upon a rigidly fixed table, placed over these dynamo- meters, was attached a recording instrument specially designed by the head of the department of steam engineering. From. this simple and yet reliable installation the power developed in the cylinders and that exerted by the propeller could be compared, By noting the thrust upon both the rotary and the thrust dyna- mometers the power expended in frictional resistance could be ascertained, it being represented by the difference in the pressures secorded. The scope of the experiments embraced the working of pro- pellers of different designs, as regards pitch, area, shape and number of the blades. Thus it was possible to secure absolute comparative data as to the power required to operate the differ- ent propellers at varying speed. It was also proposed to test the same propellers under different conditions of immersion-- which would be from as deep an immersion as the tank would permit to a condition where the blades would be partly out of water. When Prof. Biles, the eminent British naval architect and marine engineer, visited the academy in 1896, he expressed sur- prise and satisfaction at finding an installation whose cost was so slight and yet whose capabilities were so vast in securing reliable data upen this important subject. The head of the department of steam engineering at the naval academy at that time had practically but a few hundred dollars as a contingent fund, but with the aid.of the machine shop re- sources and the inventive genius of his staff of assistants, he showed the character of the original experiments that may be conducted when a well-established laboratory is in operation un- der intellisent and scientific supervision. Many more illustrations could be given as to the manner in which important experiments have been discontinued from both necessary and unnecessary causes. It is methodical, thoughtful, and persistent. work which counts, and as the German excels in this respect, the engineering world is now beginning to under- stand in its fullness the value of the work done at the German engineering laboratories in promoting German success in both naval construction and maritime development. GERMANY APPRECIATIVE OF SCIENTIFIC' RESEARCH. It is an anomaly that the greatest of military nations should be the first to appreciate the scientific attainments and capabilities of the engineer, and it is for this reason that Germany has a start of at least five years over England, France and America in syste- matic naval. engineering research. In all probability each of the three other nations has spent more money than Germany in ex- perimental work, but German expenditure, in great part, has taken place before the article is manufactured or the ship is laid down, while in the case of some rival powers, tests and expefi- ments have been conducted to discover means of overcoming avoidable defects. _ The proverbs that "an ounce of prevention is worth a pound of cure" and that "a stitch in time saves nine" are as applicable today. as they were in the last century. It is for this reason that the preparatory experimental work conducted by Germany has been productive of greater results than that done by rival powers working in the direction of seeking remedies for existing evils. The cost to the British government of using the cruisers Hyacinth, Minerva, and Hermes for comparative boiler tests and experiments will approximate more than the cost of establishing and operating both the Charlottenburg and the Dresden stations since their inception. In our navv it had been suggested to ef fect a change from in-turning to out-turning propellers of all the battleships and large cruisers in course of construction, without .