bluuebunny/crossref_metadata_2025 huggingface dataset:
Stresses in Boiler Tubes Subjected to High Rates of Heat Absorption
Authors: De Baufre Wm. L.
Published: April 2023

In order to get a more nearly accurate picture of the stresses in thick boiler tubes subjected to high rates of heat absorption, an investigation of the subject, under the supervision of the author, was made using as nearly accurate experimental data as could be found for mild steel and employing theoretically correct relations for the stresses in thick tubes. After calculating the stresses by relations derived for a constant ratio of stress to strain, the results were corrected for plastic flow in the tube wall where the stresses exceeded the elastic limit of mild steel, and also for creep which occurs when mild steel is stressed for long times at elevated temperatures. The stresses were investigated for non-uniform heat absorption around the tube circumference as well as for a uniform rate of heat absorption. Details of the investigation and the results obtained are set forth at length in the paper.
Influence of Bends in Inlet Ducts on the Performance of Induced-Draft Fans
Authors: Marks L. S. , Lomax J. , Ashton R.
Published: April 2023

This paper shows the great loss in capacity and efficiency of a fan that results from the location of elbows or bends close to the inlet boxes. The loss is shown to be a function of the type of bend, of its “aspect ratio” or ratio of depth to width, and of the direction in which the air is turned in the bend. By the use of guide vanes in the bend the loss can be almost entirely prevented. When scroll inlet boxes provided with guide vanes are used, this loss does not occur, but the capacity with such boxes is low, although the efficiency is maintained. The cause of the loss is not the friction in the bend, but is the poor distribution of the air leaving the bend and entering the inlet box. The use of a short length of straight duct between the bend and the inlet box will reduce the loss appreciably. Measurements by pitot tube of the distribution of velocity and static pressures at the entrance to the inlet boxes will indicate the existence of this loss and the desirability of inserting guide vanes in the bends.
A System for the Measurement of Steam With Flow Nozzles for Turbine Performance Tests
Authors: Moss Sanford A. , Johnson Wistar W.
Published: April 2023

In this paper the authors give particulars regarding a system of steam-flow measurement by means of a nozzle for performance tests of jet-condensing, non-condensing, or extraction turbines where condensate measurements are out of the question. The system as outlined is on a laboratory basis in order to insure the accuracy necessary when steam-turbine guarantees are involved. One of the two appendixes presents an account of tests on which the system is based; the other deals with formulas for steam flow.
The Morgoil Roll-Neck Bearing
Authors: Dahlstrom F. P.
Published: April 2023

For several years a need has existed in two-high hot rolling mills for a rugged, precision-type bearing having a capacity great enough to carry existing loads, and which could be installed in the limited space available, without reduction of neck strength. This paper reviews the experimental work with roller bearings which eventually led to the development of a unit-type oil-lubricated sleeve bearing. A brief review of pertinent laws of bearing design is included, together with their application to rolling-mill problems. Following a description of the Morgoil bearing, some results of field tests are included which show how successfully the bearing has met the conditions imposed upon it.
Carburizing With Butane Gas
Authors: Spicer C. W.
Published: April 2023

The hydrocarbon gases of the paraffin series which are being used for commercial carburizing include methane (natural gas), propane, and butane. These hydrocarbons used without the admixture of air or other gases apparently give up carbon to the steel during certain cracking processes which occur at certain rather sharply defined temperatures and other conditions. Operating conditions which give satisfactory results with one hydrocarbon may not produce satisfactory results with other hydrocarbons. These conditions are not difficult to meet when fully understood.

Well-controlled butane offers: (1) smaller temperature range than commercial solid carburizers; (2) carburizing material at low cost; (3) maximum carburizing rate at temperatures metallurgically and economically advantageous; (4) chemically constant carburizing material; (5) carburizing material requiring no complications, such as admixture of air or other gases; (6) no labor or space within the plant is required for handling or storage of solid carburizer; (7) carburizing process so free from dust and dirt that with proper furnace equipment it may be placed in the regular factory line of manufacture; (8) absolute control of depth and character of case.

The paper gives some details of the author’s experiments, certain general observations regarding the physical chemistry and a table of physical constants of the paraffin hydrocarbons, a description of a flowmeter for measuring the flow of carburizing gas to the furnace.
Effect of Reradiation on Heat Transmission in Furnaces and Through Openings
Authors: Hottel H. C. , Keller J. D.
Published: April 2023

In heat transmission by radiation, the reradiation of heat from adjacent surfaces has been a perplexing question. Radiation of heat through openings in furnace walls, radiation in electric furnaces having heating elements under the roof only, and radiation in some types of oil stills from muffles on the floor to the tubes under the roof are all cases in point. In this paper accurate methods of calculation are developed, and curves are presented from which the reradiation and total radiation factors can be read at a glance, for various shapes and proportions of radiating surfaces or openings. Incidental to the chief results, two methods of solving integral equations are presented. The theoretically developed values are checked and substantiated by actual test measurements.
Rustless-Steel Conveyors—Their Availability, Application, and Use
Authors: Elmer Nixon W.
Published: April 2023

The paper covers corrosion-resistant metals for material-handling use, giving tables of relative corrosion resistance and costs under reasonably average conditions, particularly where food products are concerned. The various available materials are briefly described, and their good and bad features and qualities are developed. The types of conveyors for which these materials have been used are given, and the important and characteristic installation features of each are discussed.
Heat-Transfer Design Data and Alignment Charts
Authors: Chilton Thomas H. , Colburn Allan P. , Genereaux Raymond P. , Vernon Harcourt C.
Published: April 2023

A search was made, during a research program on heat transfer, for the best available methods for the prediction of heat-transfer coefficients and for means of simplifying design calculations. The equations selected or developed on film coefficients are given in the paper for gases flowing in turbulent motion inside tubes, for gases flowing across tube banks, for free convection outside horizontal cylinders and at vertical surfaces, and for condensing vapors. Alignment charts are given for the solution of these equations. A simplified method of designing gas-heat exchangers was worked out on the basis of one of the equations for the heat-transfer coefficient, and a chart is also given for pressure-drop calculations made in designing heat-transfer equipment.
Canadian Pacific Railway Multi-Pressure Locomotive 8000: Its Construction, Operation, and Maintenance
Authors: Bowen H. B.
Published: April 2023

Higher steam pressures and temperatures have marked the progress toward greater power at reduced cost. Locomotive development has not kept pace with stationary practice in the use of higher pressures. After studying all available information on new types of locomotive and after investigating improved types of locomotive abroad, the Canadian Pacific Railway Company decided to construct a heavy freight locomotive for service on its severe mountain divisions. Its 2-10-4 multi-pressure locomotive 8000, which is described in the paper, was the result.
Sanforizing Process
Authors: Cluett Sanford L.
Published: April 2023

The paper describes a machine that will treat a fabric so that its dimensions in warp and filling will be what is desired after the fabric is subjected to laundry washing or other cleaning process. The causes of the shrinkage of a fabric when subjected to full laundry treatment being mostly mechanical, an effective treatment to prevent shrinking may be found in some process of mechanically rearranging the fibers of the fabric (including changing the count of warp and filling) to the same extent that the fibers would rearrange themselves if subjected to a full laundry washing. Data are given of characteristic runs of different fabrics in the Sanforizing process.
Cause and Effect of Recent Advances in Textile Machinery
Authors: Fowle Edwin D.
Published: April 2023

There is an important general advance in the improvement of textile machinery. The cause is mainly in the necessity which the machinery manufacturers face of developing equipment for replacement rather than for expansion. A slight falling off in the rate of development began this year, due largely to the great expense which the work entails, but the rate is still far above normal. If the industry will refrain from employing high-production machines to increase total output, that is to say, if it will use such equipment strictly to decrease operating costs, it will have a splendid opportunity to eliminate or reduce the overproduction which now hampers it. This is because continual renovation of the better mills will close the less efficient ones, and because reduced costs, followed by reduced selling prices, will widen the market.
Different Methods of Taking Lumber Out of Wind
Authors: Kurkjian Armen S.
Published: April 2023

Boards are generally sawed out of the green log, and although as they come off the saw carriage they are quite straight, the saw has cut some fibers crosswise, others longitudinally, or across the grain in knot formations. The strains and stresses under which the cells adjacent to the saw were confined are now released, and the exposed surfaces of the board absorb moisture or lose it, this producing warp or wind in the lumber. In the drying of this lumber the fibrous cells often become rearranged, warping it out of shape. This condition is not objectionable for certain building applications such as baseboards and trim, where the stock is nailed in place, but when making furniture, musical cabinets, case goods, etc., it is important that the permanency of the joints be assured. For this reason machinery has been devised to overcome the warp or wind in boards to be used in these ways. The paper describes these mechanical processes.
Modern Developments in Wood-Finishing Materials
Authors: Pearce M. J.
Published: April 2023

Wood-finishing materials as used today are classified according to composition, color, drying time, use, or other properties. The paper details the development work that has produced the modern finishes, and covers the purpose that they are designed to serve and the materials upon which they are used. The many stains, wood fillers, coaters and sealers, lacquers, and varnishes are described, their constituents are revealed, and their method of application is fully covered.
Trend in Aircraft-Engine Development
Authors: Caminez Harold
Published: April 2023

It is difficult to ascertain the extent to which various improvements in aircraft engines will be adopted, and it is unwise to predict what the eventual types of aircraft power plants will be. However, a discussion of present-day aircraft engines with their possibilities and shortcomings is helpful in establishing some of the trends in engine development.

The author discusses general features of aircraft engines, such as in-line versus radial types and water-cooled versus air-cooled types, and shows their limitations and advantages.
Rubber in Airplane Construction
Authors: Saurer C.
Published: April 2023

There are a large number of uses to which rubber can be put in airplane construction. Its ability to dissipate shocks and vibrations makes it useful for engine mountings, shock absorbers, and propeller insulators. It can also be used to produce a leakproof tank lining, for seat cushions, and as a lining for airplane cabins to insulate the passengers from outside noise and changes in temperature. The paper describes several types of construction in which rubber is used to advantage.
Stokers and Furnaces for New England Fuels
Authors: Foresman R. A. , Mosshart Donald J.
Published: April 2023

In this paper the authors describe and analyze some of the troubles encountered in stoker installations and discuss the principal factors to be considered in making a successful stoker installation. The discussion is limited to those problems found in New England, where the fuel used creates problems peculiarly local. The principal fuel of New England is a semi-bituminous coal, known to the trade as Pocahontas and New River coal. Among the points discussed are, selection of type and size of stoker, preheated air, furnace volume, furnace walls, ash-disposal apparatus, waste fuel, operating methods, banking, boiler operation, and recent stoker installations. Many of the points discussed receive recognition in the majority of plants, but relatively few plants recognize them all. The authors bring these practical matters together in one group.
Boiler Settings for Burning Refuse Wood
Authors: Gladden C. S.
Published: April 2023

This paper includes a discussion of: (1) Some recent developments in the design of boiler furnaces for burning green or wet refuse wood; (2) the experiences influencing the development of furnaces for burning dry refuse wood; and (3) factors influencing the design of wood-burning furnaces.
Comparative Performance of a Pulverized-Coal-Fired Boiler Using Bin System and Unit System of Firing
Authors: Grunert A. E.
Published: April 2023

An experimental program had for its object the comparative performance of a modern boiler unit, served, first, with the bin system of pulverized-coal firing and, later, with the unit system of firing, thus making possible comparisons on a common basis. The paper deals with specific types of equipment, certain types of coal, and operating conditions, influenced somewhat by local conditions. The operation of these two systems is compared in three ways—first, on an evaporative-test basis; second, on a basis of actual overall performance; and, third, on an operating-cost basis. A record of the pertinent experiences with both systems is given. Owing to the specific nature of the program, no general conclusions are given, and there is no intention to contribute to the controversial phase of the matter.
Tests of the Resistance to Repeated Pressure of Forged, Riveted, and Welded Boiler Shells
Authors: Moore H. F.
Published: April 2023

Data regarding the performance of welded joints in resisting repeated stresses are very important in any consideration of the adoption of welded construction for power boilers, and it is the object of this paper to present such data. Comparative tests were made on (1) a standard A.S.M.E. riveted drum, (2) manganese-steel riveted drum, (3) forged seamless-steel shell, (4) two forge-and-hammer-welded shells, and (5) eight fusion-welded (metallic-arc) shells, each drum or shell being subjected to applications of pressure well above the allowable working pressure.

The results indicate that under repeated stress properly made welded joints are stronger than the plates themselves when weakened by “stress raisers” such as small holes or surface defects. The tests also give useful data on the strength of drum heads when subjected to intermittent pressures.
The Performance Rating of Steam-Generating Equipment
Authors: Solberg H. L.
Published: April 2023

The demands for high capacity, high efficiency, and flexibility have resulted in the development of modern stokers and pulverized-coal burners, adequate furnaces with steam- and water-cooled walls, air heaters, steel-tube economizers, etc., and have completely changed the equipment which was used for steam generation ten years ago. Consequently the author believes it is time that the methods of expressing the performance of such equipment should be revised to conform with new conditions. Considering the problem of steam generation from the viewpoint of the functional purpose of the equipment, it appears to the author that the logical method of expressing the performance of such equipment should be on the basis of the total heat absorbed by all water- and steam-cooled surfaces per unit of time, such a method being general and applicable to all types of steam-generating equipment, and expressing the performance, not in terms of arbitrary dimensions, but of actual results produced.
Electrical-Conductance Measurements of Water and Steam, and Applications in Steam Plants
Authors: Hecht Max , McKinney D. S.
Published: April 2023

In this paper a conductance method is presented for determining the concentration of salts in steam-plant water supplies. The method is applied to determine the purity of steam, of supplies used for boiler-feed purposes, and the concentration of boiler and evaporator water. The conductance data are refined by applying both a water and a CO2 correction. The method for establishing the CO2 correction is based on the preparation of a standard “synthetic” water, and eliminates the errors accompanying the chemical analysis of “pure” water. The conductance meter used may be calibrated in terms of dissolved salts. The relation of dissolved salts to conductance is discussed. Simple commercial equipment is used for measuring conductance. The data are obtained rapidly by the steam-plant personnel, and the results may be applied easily to the control of water conditions.
Comparative Physical Properties of Chromium-Nickel, Chromium-Manganese, and Manganese Steels
Authors: Clark C. L. , White A. E.
Published: April 2023

This paper gives the results of short-time tensile tests at 75 and 1000 deg. fahr., and creep tests at 1000 deg. fahr., on certain selected steels. The steels investigated belong to either the chromium-nickel, the chromium-manganese, or the manganese series. Certain other alloying elements as silicon and tungsten were also present. The chromium-nickel steel specimens were taken from both bar and tube stock, and certain of them were tested in both the hot-rolled and water-quenched conditions.

The results indicate that the substitution of manganese for nickel in chromium-nickel steels is detrimental, at least in so far as the load-carrying ability of the alloy is concerned. Also that while the creep resistance of the manganese and manganese-tungsten steel at 1000 deg. fahr. is superior to that of many pearlitic steels, it is not equal to that of the Enduro KA2 type of alloy.
Radiant Heat Transmission Between Surfaces Separated by Non-Absorbing Media
Authors: Hottel H. C.
Published: April 2023

Fundamental laws of radiation from solids have been discussed and applied to individual problems of heat transfer in numerous papers. In this one the author indicates just what principles are involved, to how many problems they have been applied, and gives a number of applications of the principles to problems in industrial-furnace design.

Fundamental principles and definitions discussed include: The definition of normal intensity, Lambert’s cosine principle, relation between intensity and emissive power, the square-of-the-distance law, Kirchoff’s law, and the Stefan-Boltzmann law. Various surface arrangements are divided into two groups: (1) in which one of the two surfaces is small relative to the distance separating them, and (2) in which both surfaces are of considerable extent relative to their distance apart. Various cases of these and the effect of incomplete absorption are treated mathematically. The task of applying many of the equations given in the paper is simplified by presentation of numerous graphs.
Operating Experiences, Deepwater Station
Authors: Irwin K. M.
Published: April 2023

The physical characteristics of the Deepwater Plant are described, emphasizing only those details which are relatively new or those which have had a distinct bearing upon operating experiences. The paper gives a history of the operations from the time the plant was first started in March, 1930, up until the present, summarizing the difficulties that have been encountered and attempting to segregate them between those that are directly chargeable to the pressure or temperature and those which have been encountered due to other features of design. Due to the fact that a large portion of the plant has been in what might be termed commercial operating service only since June 1, or for three months at the time this paper was prepared, very little authentic data on operating efficiencies can be given.
Comparative Resistance of Refractories to Coal-Ash Slags
Authors: Hursh R. K.
Published: April 2023

The results contained herein were obtained in an investigation conducted by the Engineering Experiment Station of the University of Illinois. Tests have been made in the laboratory slagging-test furnace of various commercial refractories and of a series of special mixtures representing clays from three manufacturing districts, as well as differences in the method of fabrication, the firing treatment, and the fineness of grinding of the materials. The slags used were ashes from coals of five different districts. The comparative resistance of refractories varied with the character of the coal ash. Dry-pressed and stiff mud bricks were more resistant than hand-made refractories. A moderate degree of firing treatment was preferable to hard burning when the brick were subjected to high furnace temperatures and slag action.
High-Pressure Chemical System for Boiler-Water Conditioning
Authors: Markson A. A.
Published: April 2023

In this paper the author describes the high-pressure phosphate system for boiler-water conditioning as used at the Kips Bay Station of the New York Steam Corporation. He believes that it solves the problem of economizer deposition, and while the primary object is to avoid deposition of scale in economizers and feed lines, it is apparent that it gives a flexibility of control superior to that obtained by adding the chemical directly to the feedwater heaters or hot wells. The paper does not discuss the chemical phases of the problem.
South Amboy Plant of the Jersey Central Power and Light Company
Authors: Roe R. C. , Mailler J. P.
Published: April 2023

The Jersey Central Power & Light Company, an operating unit in the Middle West Utility System, has just put into operation a new plant on the Raritan River at South Amboy, N. J., designed and constructed by the Electric Management & Engineering Corporation of New York City. This plant at present consists of two 25,000-kw. vertical-compound turbines with condensers and all auxiliaries and three 280,000 lb. of steam per hr. boilers, furnaces, and accessories, operating at 1400 lb. pressure. Space has been provided for the installation of a third turbine within the station which is approximately 168 ft. square and 110 ft. high to the boiler-room roof and is constructed along modern architectural lines.

The plant is located at the geographical center as well as the load center of the system and will, when the transmission lines are completed, serve as a base-load plant for both the Northern and Southern divisions, which at the present time are operated as independent divisions.
A Generation of Progress in Human Engineering
Authors: Hanley William A.
Published: April 2023

In this paper the author has considered two manufacturing plants of about the same size, and in the same state, and contrasted conditions under which labor worked in these factories 30 years ago and conditions as they are today. The subjects covered deal with nearly every phase of factory employment. Some interesting conclusions are drawn.
Flange- Versus Foot-Mounted Motors
Authors: Chase Herbert
Published: April 2023

Advantages in favor of flange mounting given by the author include: improved appearance, compact arrangement, more rigid mounting, saving in weight, less cost, better alignment, more easy attachment, and better protection against oil, chips, and dirt. Full advantage cannot be taken of the benefits of flange mounting until some effort at standardization is made. Motor manufacturers can easily bring about such a standard to their own benefit and to the benefit of machine manufacturers generally, and the latter, it is believed, will readily accept such a standard.
Handling Bulk Materials Mechanically
Authors: Sayers William W.
Published: April 2023

The paper outlines the general characteristics and fields of applicability of the numerous types of mechanical handling and conveying equipment. It also covers the types commonly used for handling such bulk materials as coal, coke, sand and gravel, crushed stone, lime, cement, phosphate and fertilizer, grain, cottonseed, sugar, earth, foundry sand, etc. No attempt has been made to cover overhead cranes and hoists, crawler and locomotive cranes, and such dock handling equipment as bridge tramways, unloading towers, lift-type car dumpers, etc., all of which are also used for handling bulk materials mechanically.
The Diesel-Engine Tractor and Excavator
Authors: Rosen C. G. A.
Published: April 2023

Special emphasis is given in this paper to the combustion process for Diesel-tractor service. A variety of fuel systems were installed and tested in a rugged engine of flexible design. General results of the tests are given. Accessories are considered extremely important in tractor service, and the author discusses air cleaners, oil filters, and engine starters. The problems discussed can be applied to other traction equipment including excavators. Reliability at all loads and speeds within the engine operating range is paramount, and maintenance costs must be kept low.
Development of the Double-Acting Engine
Authors: Ford Louis R.
Published: April 2023

In less than a decade there has been development of the Diesel double-acting engine into a reliable prime mover. Double-acting engines for large power-plant work are attracting attention. A committee studying types of equipment for the extension of the Copenhagen electric-power station has recommended acceptance of a Burmeister & Wain double-acting, two-cycle engine of 18,500 b.hp., with continuous overload capacity of 22,500 b.hp. At present the two-cycle type has forged ahead of the four-cycle design. The steps in the development of the double-acting engine are reviewed by the author.
Use of Superheated Steam in Oil-Well Drilling
Authors: Smith V. Weaver
Published: April 2023

Advent of deep drilling for oil has greatly increased the size of the equipment necessary for drilling. The cost of equipment has been mounting very much faster than the return from the wells. Furthermore, the transportation of this heavy equipment is becoming a serious problem. These factors have turned the oil industry to the engineer for assistance in solving the problem of reducing the cost of drilling wells.

Conditions have become so serious that in spite of the fact that the driller pays nothing for his fuel, he is now able to buy power in some cases from public utilities, who pay for this same fuel, more economically than he can produce it. This condition has been brought about because little attention has been paid to decreasing the initial cost and increasing the life of the equipment. Utilities have overcome the fuel cost by more efficient design and operation of the power-plant equipment. The producing industry is in an excellent position to reduce the cost of drilling wells by taking advantage of the improvements that utilities and other industries have made in design of power equipment. By so doing they will recover the advantage of low or no fuel cost, and thereby reduce the cost of drilling.
The Work Factor of Lubricating Oil
Authors: O’Neill James G.
Published: April 2023

The usefulness of the standard laboratory tests in judging the quality of lubricating oils in the past has been limited, due to widely different crudes from which lubricating oils are produced and to the varied processes used in their refinement. The new method proposed for evaluating lubricating oils seeks to extend the application of the standard laboratory tests in that their results will indicate the service that will be obtained from the oils in actual operation. Increases in viscosity, neutralization number, precipitation number, and per cent of carbon residue of a lubricating oil when subjected to an endurance test, which simulates service conditions as found in a forced-feed lubrication system, are expressed numerically by means of formulas, and the average of these results is called the work factor of the oil. A description of the method and apparatus of the endurance test is given, and the concordance of results obtained is shown when different machines are used to test the same oil. The work factors of turbine, Diesel-engine, and aviation oils are discussed with relation to their performance in actual service. The Navy method for purchase of lubricating oils employing the work factor is discussed, as also are the advantages derived from the use of the work factor.
Standards and Tests for Coated Abrasives
Authors: Schacht E. C.
Published: April 2023

The paper presents some of the standardization measures which have been undertaken by the sandpaper industry, tracing their evolution and influence on the product. Typical factory-control methods used in the manufacture of coated abrasives are described, together with testing media for evaluating the cutting efficiency of the finished product.
Need of Forest-Products Engineers in the Woodworking Industries
Authors: Brown Nelson C. , Hoyle Raymond J.
Published: April 2023

For many years it was thought that a forester had to do only with the growing and handling of the forest crop. Now the forest schools recognize that the utilization of wood products, including the conditioning, remanufacturing and merchandising of various forms, is just as important a part of forestry. To meet this situation, the curricula of some of the forest schools are changing. The woodworking industries have problems that need solution. Trained men who know about the technological features of wood are needed. In some way the forest schools have failed to train men to meet the demand in these wood-using industries. It is also felt that the industries have failed to cooperate with the schools in order to have the courses fit in with their needs. Closer relationship, however, is growing up between the industries and the forest schools.
Grading Timber for Strength
Authors: Ericksen Leyden N.
Published: April 2023

The paper deals with the development of grading rules for structural timbers, the principles involved, effect of structural features on strength, and the application of the principles in commercial practice. Structural grading rides are based on the provisions of the American Lumber Standards, developed by the combined efforts of lumber producers, distributors, specifiers, and consumers, under the auspices of the U. S. Departments of Commerce and Agriculture. Structural material is divided into classes according to size and use: horizontal load-bearing members such as joists, planks, beams, and stringers, and vertical compression members, as posts and columns.

The strength of wood members is influenced by the density of the wood, moisture, seasoning, and the size, location, and number of strength-influencing factors present, such as knots, shakes, checks, and slope of grain. Heartwood, sapwood, and wane are more important from other points of view than for their influence on strength. Principles of structural-material grading have been applied in a practical manner by lumber-manufacturers’ associations in drawing up commercial grading rules.

Safe working stresses for various grades and different conditions of exposure have been established in accordance with strength of clear wood, effect of strength-influencing factors permitted, the effect of seasoning, time of loading, and the characteristics of each species. Basic principles can also be applied to general construction material carried in retail lumber yards, thus insuring maximum strength and efficient utilization.
Utilization of Wood Waste in the Chemical Industries
Authors: Fogler Ben B.
Published: April 2023

The principal uses, other than for fuel, for the wastes from the sawmill and woodworking industries are found in the following chemical industries: Destructive distillation, the manufacture of pulp, paper, and building boards, and those industries consuming large quantities of wood flour, principally linoleum, plastics, and explosives. The technical aspects of this waste utilization have been so satisfactorily worked out that a project of this sort may be evaluated almost entirely from the economic side. Competition from other raw materials, together with certain economic factors, requires that all of these operations be based on an ample, well-located, and relatively long-lived supply of waste wood. In many of these processes the waste wood must be separated either as to size or as to variety, although in some cases similar varieties may be processed together.
The Aircraft Diesel Engine
Authors: Griffith Leigh M. , Vincent Edward T.
Published: April 2023

In this paper the authors present information to show that the Diesel or fuel-injection engine in some of its modified forms is well adapted to the requirements of airplane and airship propulsion. They believe that its first and most important commercial application will be in relatively large units on large aircraft and that increased fuel economy, both as to weight and cost, will be an important factor in the progress of commercial air transportation. They consider that the greatly reduced fire hazard will be an important factor in the development of quantity air transport of passengers and that the absence of radio interference will greatly simplify the problems of navigation and communication. The potential advantages of two-stroke cycle operation will be realized in the Diesel engine. In large airplanes from one to three engines of large size will be used, and these will be mounted and enclosed so as to allow of attendance during flight. Such engines will be fluid-cooled, either by liquid circulation or evaporation. The service reliability of the Diesel, they believe, will exceed that of the carbureted, air-cooled engines inaccessibly mounted, and the problems of weight and cost are less serious than are generally supposed, and will soon be solved commercially.
Factors in the Design of Commercial Airplanes
Authors: Porter Charles Talbot
Published: April 2023

A steady and profitable market may be expected for existing equipment in remote and inaccessible places, where other forms of transportation are not available, but the real problem is to make the air transport compete successfully with the extra-fare trains. The real commodity that is being sold is transportation, and the factors involved are speed, comfort, and cost, assuming of course that safety and reliability have been demonstrated. The combination of these three factors must equal that of the fast train. The cost of air travel is of necessity high; therefore the speed-comfort combination must exceed that of the railroads. In general, the comfort of the train at least equals that of the airplane, so the latter must be sold on the speed factor alone, without sacrifice of a certain minimum requirement for comfort and at a cost that is justified by the increase in speed.

Existing air transports have a high speed of 135 to 145 miles per hour, a capacity of ten to twelve passengers, and a power output of 100 hp. per passenger. The speed has been obtained by increasing the power per passenger to nearly double that formerly thought sufficient. High power means high fuel capacity and decrease in percentage of pay load.

The author advocates the development of a 30 to 40 passenger airplane that will equal present speed requirements with a reduction of power to 50 to 60 hp. per passenger. To obtain this result he advocates abandoning direct-drive air-cooled radial engines and replacing them by geared engines, air-cooled or liquid-cooled, placed preferably inside the wing, with a remote drive to the propellers. The airplane itself should approach the flying wing, the wing loading should be high, and the landing gear should be retractable. Due to increase in landing speed the brakes should be much larger, should be operated by mechanical power, and should be capable of utilizing the full friction between the wheels and ground. The material from which the airplane is made will depend largely on a depreciation factor which is not yet clearly defined and cannot be set up until large airplanes have been in operation for a longer period of time.
Seaplane Design
Authors: Wright T. P. , Luburg G. A.
Published: April 2023

The design of the seaplane is given in detail, and the advantages of its use are described. The seaplane can generally find a landing place nearer to the center of large cities than can the land airplane. The flying boat, it is predicted, will ultimately be the method of air travel across the oceans. The market for the flying boat and the amphibian is waiting for development by the manufacturer and operator.
Airplane Design, Manufacture, and Sales, Commercial vs. Military
Authors: Beisel Rex B.
Published: April 2023

The commercial industry differs materially from the military, and the paper discusses these differences from the general standpoint of design, manufacture, and sale. It would be a great deal more difficult for the commercial builder to enter the military field than for the maker of military airplanes to successfully enter the general commercial field.
The Construction and Operation of Gliders
Authors: Budwig Gilbert G.
Published: April 2023

The construction, operation, and maintenance of gliders present problems for which there is little precedent. From the regulatory standpoint, the rules of the Department of Commerce will permit licensing of those built prior to October 1, 1930, by passing a satisfactory visual inspection and test. After that time, the construction of gliders will come under more severe rules for licensing.
High-Performance Gasoline Aircraft Engine: Its Problems of Fuel, Oil, and Materials of Cylinder Construction
Authors: Heron S. D.
Published: April 2023

The paper discusses the available fuels and anti-knock compounds for aircraft use. The question of the anti-knock values of widely different fuels is one concerning which but little is known. The determination of these knock values was the object of the experiments conducted.
Aluminum Alloys for Aircraft-Engine Piston and Cylinder Heads
Authors: Lyon A. J.
Published: April 2023

The paper contains results of a great amount of valuable research on aluminum alloys for aircraft-engine piston and cylinder heads that has not heretofore been covered, and the findings should be valuable to all aircraft-engine designers. Two alloys have heretofore been recommended, but the Materiel Division at Wright Field has developed a series of new alloys, and the paper describes the method of manufacture, the effect of numerous alloying constituents on their properties, the strength at elevated temperature, their stability, and the methods of heat treatment, with comparison with the present standard alloys.
Engineering Computations for Air and Gases
Authors: Moss Sanford A. , Smith Chester W.
Published: April 2023

In this paper the authors give methods of making the usual engineering computations for adiabatic compression, expansion, flow through measuring nozzles, and similar work concerned with the thermodynamic properties of air and gases, in the minimum amount of time and with the greatest accuracy possible with engineering methods. The theoretical formulas needed are included, together with extensive tables for use in computation.
Longitudinal Wave Transmission and Impact
Authors: Donnell L. H.
Published: April 2023

When a force is applied to a body, waves of stress and velocity radiate through the body from the point of application of the force. When these waves strike the boundaries of the body they may be wholly or partially transmitted to surrounding bodies or reflected back into the body, where they may reverberate back and forth within its confines, like sound waves within the body of air in a closed room. By superposition of these radiated and reflected waves the stress and motion of all parts of the body are gradually, and in general discontinuously, brought up to the values ordinarily assumed.

In the case of a small body this whole process takes place so quickly that there is great difficulty in detecting it, and generally it is of little practical importance. But there are cases where it is desirable to study the process in detail, particularly when the dimensions to be dealt with are no longer very small compared to the velocities of such waves, and in consequence the time element is no longer negligible, or where the time of application or variation of applied forces is very small and hence of the same order of magnitude as the aforementioned time element, as in cases of impact or harmonic forces of considerable frequency. In the present paper an attempt is made to consider some of the more important phases of this subject in as simple a manner as possible.
Economics and Design of Water-Cooled Furnaces
Authors: Bennett J. S. , Oberholtzer P. N.
Published: April 2023

Experience of one manufacturer in designing and operating water-cooled furnaces is given in this paper. It deals particularly with water-cooled furnaces for underfeed stokers, and a study of results and conditions of several actual installations is presented. Determination of the proper amount of water cooling is an economic rather than a combustion problem. Ordinarily the most critical portion of the furnace is the rear wall, so that if but one wall is to be cooled, it should be the rear wall. Sometimes the sizes of stokers used in older-type plants are limited by the ability of the furnace to withstand temperatures resulting from higher combustion rates. In many such cases a moderate investment in water cooling will give a substantial increase in steam output.
Mechanical and Human Elements in Smoke Abatement
Authors: Fisher George C.
Published: April 2023

A brief description is given of the history of the work of smoke abatement in Nashville, with the local conditions and the technical details and the general policies followed. The greater part of the paper deals with the human elements that entered into the problem of enforcement and the educational features that were planned and carried out to put smoke abatement into effect.
Photo-Electric Smoke Recorder
Authors: Griffin V. P. , Breisky J. V.
Published: April 2023

The paper discusses the necessity of measuring smoke density in the stacks of power plants, so as to enable the operator to keep the smoke down to a minimum. Methods of smoke determination that have been available in the past are described. All of these methods depend on the human eye for judging the smoke density, and are influenced by weather conditions, being entirely inoperative at night. The necessity of a continuous and permanent record is brought out, a feature which has not been available in apparatus heretofore in use.

The photo-electric smoke recorder is then described. The scheme of operation is to project a beam of light through the stack or the breeching on a photo-electric cell. Depending on a lighter or heavier density of smoke in the stack, the photo-electric cell, popularly called the “electric eye,” receives more or less light, which causes a greater or smaller current to flow through the cell. This current is then amplified so as to be sufficiently large to operate a standard indicating and a recording meter. These meters can be located at any desired point.

This device gives a continuous indication as well as a permanent record of smoke density, and also sounds an alarm or lights a lamp whenever the smoke density approaches a predetermined value. It works equally well day or night and is independent of weather conditions.

Operating results, including chart records of several installations, also are given, showing that smoke can be reduced to a minimum in a well-designed and properly operated plant.
Use of Fuel in the Manufacture of Portland Cement
Authors: Reid H. P.
Published: April 2023

Heat is required in the manufacture of Portland cement for evaporating the water from the coal and from the raw materials used in making the cement; for preheating these materials to temperatures necessary for calcination; for breaking up the carbonates and oxidizing the undesirable elements, principally organic matter, from the raw materials; for further raising the temperature of the material to the point necessary to effect the desired chemical reactions; and for producing the power required for mechanical operation. All of these requirements except that of removing the moisture and the production of the power are met inside the cement kiln, and are commonly included in the term “burning.” Furthermore, with the wet process the moisture is evaporated in the kiln also.
Electrically Heated Hardening and Tempering Baths Compared With Fuel Methods of Heating
Authors: Scott Wirt S.
Published: April 2023

Necessity for uniform products and improved working conditions led the Warren Axe and Tool Company to replace its fuel-heated furnaces with electrically heated types. A reduction in costs of manufacture has also resulted, so that, based on actual book profit, the new equipment will pay for itself in 18 months. The new equipment, its control and operation, is described in this paper.
Heat Reaction in the Boiler Furnace
Authors: Wohlenberg W. J.
Published: April 2023

This paper attempts to point out only a few of the angles from which the modern art of boiler design may be viewed. Each important case must be specially investigated, for there are no hard-and-fast rules that may be applied, and many empirical data must still be relied upon in determining proportions that will result in satisfactory operation. The future will require that students become acquainted with certain broad underlying principles reached through such methods of analysis as are hinted at in this paper.
Effect of Large Boilers at High Capacities on Operating Characteristics and Investment in Boiler Plants
Authors: Clark Frank S.
Published: April 2023

This paper treats of the various factors that enter into the design of boiler plants, their effect on investment costs and on operating characteristics. It traces the development of the boiler plant from a number of small units operated at moderate capacities to the present plant of a few large units run at high rates of evaporation. It gives the conditions that limit the sizes and output and shows how, as the demand for larger units increases, these conditions have been overcome. The paper shows the effect of large units in reducing the sizes of buildings to house them, and the number of auxiliary equipment to serve them. It shows the effect of reliability of equipment on increased service factor, with consequent reduced necessity for spare equipment. It states that the governing factors in investment costs for a given condition are the size of the unit and the output obtainable, the former depending on the ability to manufacture, and the latter on the fuel that can be burned in the furnace and the ability of the unit to absorb the heat. Further, it discusses the proportioning of heat-absorbing surfaces between boiler, economizer, and air preheater to obtain the most economic result at minimum cost, and also the effect on operation of large units run at high capacity, and in turn their effect on labor and maintenance cost.