been obtained. In addition to the data relative to the battery requirements, the interpretation of the records has indicated the possibility of using this method for the study of lubrication, and engine problems relating to speed, friction, ignition, compression, and distributor action. Oscillograms obtained for five of the cars measured are shown in the illustrations. The results given are intended to be suggestive rather than quantitative measurements of performance. (May 2, 1921.) 23 pp. Price, 10 cents. T187. A Study of Test Methods for the Purpose of Developing Standard Specifications for Paper Bags for Cement and Lime. . ... ...Paul L. Houston In this study, new test methods are developed for giving numerically the stress and strains that cement and lime bags undergo in service. There is also given a new test for determining the strength of the adhesives used in these bags. This paper also includes ordinary physical and chemical tests, and specifications are drawn up as a conclusion. (Mar. 21, 1921.) 19 pp. Price, 5 cents. T188. Some Properties of White Metal Bearing Alloys at ... John R. Freeman, Jr., and R. W. Woodward An apparatus is described for determining the yield point and ultimate strength of white metal bearing alloys at temperatures up to 100° C. The results of compression tests and Brinell hardness at temperatures up to 100° C are given for five typical white metal bearing alloys including three tin base alloys, one lead base alloy, and one intermediate alloy which show that the tin base alloys maintain their properties better at elevated temperatures than the lead-containing alloys. The yield point of tin base alloys is not affected by heating for six weeks at about 100° C, but the yield point is lowered in the lead base alloy by heating for two weeks at about 100° C. (Apr. 5, 1921.) 16 pp. Price, 5 cents. T189. Method for Differentiating and Estimating Unbleached Sulphite and Sulphate Pulps in Paper. .R. E. Lofton and M. F. Merritt A short review of methods recommended at various times for differentiating between unbleached sulphite and sulphate fibers, and a descriptions of a new method for determining the presence and approximate amount of these fibers in pulps or paper. (Apr. 4, 1921.) 18 pp. Price, 5 cents. T190. "Black Nickel" Plating Solutions. George B. Hogaboom, T. F. Slattery, and L. B. Ham To produce the so-called government bronze finish on military hardware, "black nickel" plating was frequently applied. Investigation showed that for this purpose very complicated solutions were frequently employed and at times great difficulty was encountered in producing uniform results. This paper describes the results of a few experiments upon such solutions and contains recommendations regarding the composition and conditions of operation which will yield satisfactory deposits. (Apr. 4, 1921.) 9 PP. Price, 5 cents. T191. Some Factors Affecting the Life of Machine-Gun W. W. Sveshnikoff Star gage measurements on six machine gun barrels at various stages of firing indicate that when the life limit is reached exhaustion is due to a combination of the abrasive action of the bullet and the abrasion of gases. Amorphous martensite on the surface of the bore has been reproduced by the high temperature from an electric arc, its formation being due to the extremely rapid cooling caused by the large mass of cold metal near the highly heated surface. Cracking of the bore is due to dimensional changes of the hardened brittle surface of the steel resulting from the variations in temperature between separate shots. The cracks originate at irregularities of the surface of the bore. (June 4, 1921.) 27 pp. Price, 10 cents. T192. Tests of Centrifugally Cast Steel... George K. Burgess Six castings manufactured by the Millspaugh centrifugal process were examined as to their physical and chemical properties, including hardness, tensile strength, impact resistance, density, internal stress, segregation, soundness, and microstructure, both in the condition as cast and after various heat treatments. This investigation shows the possibilities of substituting heat treatment for forging in this type of casting. (June 7, 1921.) 22 pp. Price, 10 cents. T193. Design of Atmospheric Gas Burners.. Walter M. Berry, I. V. Brumbaugh, G. F. Moulton, and G. B. Shawn This paper describes the apparatus and methods used for the investigation of burner operation. Several types of gas orifices were investigated and the coefficients of discharge determined. The principles governing air injection are discussed, and examples and curves are shown to illustrate the effect of a change in the gas pressure, specific gravity, and volume of gas. The design of injecting tubes that produced the greatest injection of air was determined. Characteristics of a satisfactory burner are described. The relation between total port area of burners and the capacity of burners is fully discussed. (Sept. 6, 1921.) 62 pp. Price, 15 cents. T194. A Preliminary Study of Tearing Instruments and Tearing Test Methods for Paper Testing. .Paul L. Houston In this technologic paper a study is made of the relative effect of different sizes of test samples on the tearing strength of paper. Data are presented to show that the larger the test samples, the greater are the values of tearing strength. There is also taken up a study of two types of tearing instruments on the market. The degree of accuracy of each instrument is determined, and the errors are plotted in the form of curves. In the conclusions, the good and bad qualities of these instruments are discussed at length. (July 27, 1921.) 18 pp. Price 5 cents. T195. Zinc Cyanide Plating Solutions. ...William Blum, F. J. Liscomb, and C. M. Carson During the war zinc plating (or electrogalvanizing) was extensively applied for the protection of steel against corrosion. For this purpose zinc sulphate or zinc cyanide solutions may be employed, but the latter produce more uniform distribution of the metal upon irregular shaped parts. This paper describes the results of experiments upon the preparation, analysis, and operation of zinc cyanide plating solutions. (Aug. 17, 1921.) 19 pp. Price 5 cents. T196. High Fire Porcelain Glazes... .H. H. Sortwell An investigation of a large field of porcelain glazes with varying alumina and silica to determine the limits within which lie high fire porcelain glazes suitable for use on high fire porcelain, chemical porcelain, spark plugs, pyrometer tubes, etc., maturing from cone 10 to cone 16. (Sept. 2, 1921.) 13 pp. Price, 5 cents. T197. Cementing Qualities of the Calcium Aluminates .P. H. Bates The four calcium aluminates (3CaO.Al2O3, 5CaO.3Al2O3, CaO.Al2O3, 3CaO.5Al2O3) have been made in a pure condition and their cementing qualities determined. The first two reacted so energetically with water that too rapid set resulted to make them usable commercially. The last two set more slowly and developed very high strengths at early periods. These two aluminates high in alumina were later made in a pure and impure condition in larger quantities in a rotary kiln, and concrete was made from the resulting ground clinker. A 1:1.55.5 gravel concrete developed in twenty-four hours as high strength as a similarly proportioned Portland cement concrete would have developed in twenty-eight days. (Sept. 27, 1921.) 27 pp. Price, 10 cents. T198. Results of Some Tests of Manila Rope. ..Ambrose H. Stang and Lory R. Strickenberg This technologic paper gives a summary of the results of tensile tests of 368 specimens of Manila rope. Most of them represented material submitted on purchase orders for Government departments. They were all threestrand regular lay Manila rope having diameters from 1⁄2 inch to 41⁄2 inches. A summary of the results is given in tables and also graphically. A formula is given by means of which the breaking load for any diameter of rope may be estimated. (Sept. 15, 1921.) 11 pp. Price, 5 cents. T199. Method for Precision Test of Large Capacity Scales... C. A. Briggs and E. D. Gordon This paper outlines a scientific and systematic method used by the Bureau of Standards for testing railroad master and grain hopper scales. A pointer and scale are arranged for reading the position of the beam; and the errors of the scale are determined from observations made upon the freelyswinging beam. The procedure of the test is explained with the aid of a record form and computation sheet which was developed in connection with the successful application of the method in the field. In the interest of a uniform and efficient method the scheme outlined is recommended for adoption by those who have occasion to carry out tests on large scales where accuracy of a high order is required. (Sept. 24, 1921.) 16 pp. Price, 5 cents. T200. An Investigation of Oxyacetylene Welding and ..Robert S. Johnston At the request of the War Department the Bureau conducted an investigation of the operation, efficiency, and safety of oxyacetylene welding and cutting blowpipes. Apparatus from fourteen different makers was submitted to tests, developed jointly by the Bureau in cooperation with makers. The blowpipes were tested in a standard manner to minimize personal equation of the operator and secure data which was representative of the blowpipe itself. It developed that the principles upon which the design of such blowpipes should be based were not well understood, and useful conclusions were reached which should be useful to the industry. (Dec. 28, 1921.) 108 pp. Price, 35 cents. T201. Friction and Carrying Capacity of Ball and Roller Bearings......H. L. Whittemore and S. N. Petrenko The experiments were undertaken by the Bureau of Standards at the suggestion of the Navy Department to determine the maximum safe load, and the static friction under load, of ball and flexible roller bearings. Tests were made on balls of 1.00, 1.25, and 1.50 inches diameter in grooved races and on rollers 1.25 inches in diameter and 5.25 inches long in flat and cylindrical races. The ratio of friction to load is practically constant and equal to 0.00055 for all three sizes of balls up to a 'critical" load which varies with the diameter of ball. A similar "critical" load, 25 000 lb., was found for the roller bearings with a ratio of friction to load equal to 0.00075. (Oct. 6, 1921.) 34 Pp. Price, 10 cents. T202. Results of a Survey of Elevator Interlocks and an ...C. E. Oakes and J. A. Dickinson This report presents the results of an inspection of the interlocking mechanisms on several thousand elevator landings, the performances being classified into groups on a basis of service and maintenance conditions—a comparison of the advantages and disadvantages of the various types of devices is given, together with causes of breakdown under service. A number of tables of elevator statistics are given, the statistics being further classified "shaft-door" and "nonshaft-door." A general discussion of the statistics follows. The interlock requirements of the A. S. M. E. Elevator Code are quoted in conclusion. (Oct. 17, 1921.) 30 pp. Price, 5 cents. as T203. Influence of Phosphorus upon the Microstructure and ...Edward C. Groesbeck In this investigation, no clear relationship could be established between the phosphorus content, varying within the range 0.008-0.115 per cent which marks the usual limits in plain carbon steels, and the microstructure and hardness as developed in two series of specimens, one of basic open hearth steel and the other of acid open hearth steel, by a series of different heat-treatments because of the marked irregularity in the distribution and grain-size of the ferrite and pearlite grains found present in many of the specimens. This irregularity was traced to the nonuniform distribution of the phosphorus. A cellular-like structure formed in conjunction with the microstructure normal to these steels was studied, and relationship between this unusual structure and the distribution of phosphorus was established. (Nov. 21, 1921.) 33 pp. Price, 10 cents. T204. Cutting Fluids... .Eugene C. Bingham Cutting fluids are used both to cool and lubricate. When lubrication is the more important, it is generally recognized that fatty oils are superior to mineral oils, although the reason has never been clearly explained. The evidence appears to be that the value of fatty oils is due to their acidity which causes the adhesion to metal to be greater than is the case with mineral oils. If this should prove to be the case it may yet be possible to synthesize an oil which has all of the virtues of lard oil without its obvious defects. (Dec. 21, 1921.) 44 Pp. Price, 15 cents. T205. Tensile Properties of Some Structural Alloy Steels at High Temperatures... .H. J. French Gives the results of determination of tensile strength, proportional limit, elongation, reduction of area, and strength at fracture throughout the range 20 to 550° C for four steels containing about 0.38 per cent carbon, as follows: Plain carbon steel; 31⁄2 per cent nickel steel; 3 per cent nickel, I per cent chromium steel; and I per cent chromium, 0.2 per cent vanadium steel. Brief reference is made to the type of fractures obtained in testing steels at various temperatures and particular attention is paid to comparison of the tensile properties of these alloys at 550° C. (Dec. 20. 1921.) 18 pp. Price, 5 cents. T206. Effect of Heat-Treatment on the Mechanical Properties of One Per Cent Carbon Steel.. H. J. French and W. Geo. Johnson The effects of varying time-temperature relations in heat-treatment on tensile, impact properties, hardness, and structure of 1 per cent carbon steel have been studied, including (a) effect of temperature variation in hardening, (b) time at hardening temperatures both above Acm and between the Ac, and Acm transformations, (c) effects of tempering steel hardened in different ways and effects of "soaking" just under the lower critical range, (d) comparison of oil and water hardening for production of definite strengths. (Dec. 27, 1921.) 31 pp. Price, 15 cents. T207. Manufacture and Properties of Steel Plates Containing Zirconium and Other Elements. . . . ..George K. Burgess and Raymond W. Woodward The mechanical properties and microstructure of 193 experimental heats of steel containing as principal variable elements C, Si, Ñi, Al, Ti, Zr, Ce, B, Cu, Co, U, Mo, Cr, and W have been studied. Extremely high tensile properties with excellent ductility and toughness can be obtained from a nickel-silicon steel without the addition of expensive alloying elements. A method is described for the chemical analysis of steels containing zirconium. (Feb. 1, 1922.) 54 pp. Price, 20 cents. CIRCULARS [All Circulars are subject to revision to keep the subject matter current. Inserted in this list of publications is a supplement giving the latest data concerning the latest editions of the Circulars. For example, the supplement gives for each Circular the Circular number, the latest edition number, date, number of pages, and price. The supplement also gives any modification required in the descriptive abstract for revised editions of Circulars. For publications in following list that are out of print, see the supplement to this Circular.] CI. (Now in preparation. Will cover the organization, functions, and work of the Bureau.) C2. Measurements of Length and Area, Including Thermal Expansion. Gives the regulations under which length and area measuring apparatus, such as engineers' tapes, yard and meter standards, end standards, machine-shop gages, precision screws, and calipers are tested by the Bureau, shipping directions, schedule of fees, etc. The fundamental standards of length are described, the inter-relationship of the various units of length is given, and the methods of comparisons of length standards are outlined. C3. Design and Test of Standards of Mass. Contains general information on the fundamental standards of mass; a classification of weights into groups according to use (industrial or scientific); tolerances, and specifications for the construction of weights in each class; a discussion of the several methods of testing and adjusting weights; tables and formulas for correction of weighings for the buoyancy of the air, etc. The regulations governing the testing of weights by the Bureau of Standards and a schedule of fees for such testing are included. C4. Verification of Standards of Capacity. Gives shipping directions and a schedule of fees for metal capacity measures tested by the Bureau of Standards. C5. Testing of Clinical Thermometers. The edition of July 16, 1917, is considerably revised to announce new regulations, effective July 1, 1917, governing the certification of clinical thermometers. Past practice was to issue certificate in the form of a table of corrections at four points, 96°, 100°, 104°, and 108° F; the new certificate will be issued only for thermometers correct within 0.1° F at normal and 0.2° F at 104 and will contain the statement that the thermometer is correct within these tolerances. The Circular contains a full description of the method of testing clinical thermometers and considerable matter of general interest concerning these instruments. C6. Fees for Electric, Magnetic, and Photometric Testing. States the kinds of tests performed and gives the fees established by the Bureau for tests of electric, magnetic, and photometric standards, measuring instruments, and materials. It supersedes the schedules of fees given in older editions of the various circulars upon these subjects, editions of which have been published since 1913 without the lists of fees. The fundamental units used as the basis of measurement are summarized. Specific instructions are given as to arranging for tests and shipping apparatus. C7. Pyrometer Testing and Heat Measurements. Information is given concerning the high-temperature scale, including a list of melting and boiling points suitable for calibration of pyrometers. Descriptions, precautions in use, and the methods of calibration of the various types of pyrometers are given, including thermoelectric, electrical resistance, optical, and radiation instruments. There is also given a list of the tests in heat measurements that the Bureau is equipped to carry out. |