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A brief summary of the history of motor rail-car equipment on the railroad represented by the author is given in his paper. Three gasoline-driven rail-cars were put into operation in 1910. The engine used for each car was a six-cylinder, 10 x 12-in., slow-speed, four-cycle reversible-type having overhead valves, an open crankcase and a 200-hp. rating, but experience has proved that the four-cycle reversible-type engine equipped with an air-operated starting-apparatus makes rather a complicated unit that is the cause of many difficulties. Details are given concerning these first three cars, their performance and the changes made in their equipment. In 1922, a two-car train consisting of a motorcoach and a trailer was installed. The coach is 28 ft. long, has a 12-ft. baggage-space, carries 30 passengers and weighs 28,000 lb.; the trailer is 32 ft. long, weighs 17,000 lb. and seats 36 passengers.

Solicitation of sales and the delivery of the product to the customer constitute the most important operative features of the motor-truck fleet supervised by the author. Endeavor is made to install the vehicles in the various fields along standardized lines. The volume and the extent of the business and the topographical conditions of each locality determine the size and the mechanical equipment of the vehicle that is employed, and it is installed only after a study of all the conditions pertaining to its operation. Adequate training of vehicle operators, not only along mechanical lines but also as direct sales representatives of the company, is made a feature; and so is accident prevention. These interests are promoted in various standard ways and are furthered by the publication of “house organs.” After a vehicle is installed the slogan adopted is: Keep It Moving With a Pay Load.

In the first part of the paper, a general quantitative comparison of air, water and oil-cooled cylinders is given as it relates to the subject of heat-transfer and temperature drop. Unfortunately, the discussion does not include experimental data, but the assumptions are stated clearly and a large range of values is covered in Table 2 so that any desired values can be chosen. A thorough and comprehensive discussion of the steam or the radio-condenser type of cooling is given under the headings of Steam Cooling Systems, Characteristics of Steam Cooling Systems, Cooling Capacity of Radiators Used To Condense Steam and Present State of Development. In the second part, an attempt is made to give a thorough but brief discussion of the performance or of the operating characteristics of radiators from the point of view of the car, truck or tractor designer. The cooling of aircraft engines is not considered.

The quality of plated steel may be tested by exposing the article to the action of a salt spray and noting the appearance at intervals. A numerical method of rating the appearance is presented, and the rust resistance of steel plated with nickel and copper is shown to be dependent on the thickness of the plating. The effect on the salt-spray resistance of some common variables in nickel-plating, such as boric acid, ferrous sulphate, current density and defective steel, is disclosed and charted. The need of close technical control of the plating process is indicated, and some of the advantages of controlled electroplating at high current-densities are set forth.

Recent improvements in the mechanical equipment and the processes employed in the various car-assembling plants of a large motor-car-building company are described. As a result of the changes these departments have been transformed from the most unsightly parts of the factory into the cleanest, most comfortable and least dangerous. The processes to which special attention is devoted are those for the enameling of fenders and sheet-metal parts and such small parts as various stampings, forgings and malleables and cover the application of two coats of an asphaltic-base enamel and a subsequent baking at about 450 deg. fahr.; in body enameling they cover the application of three coats of similar material and baking at from 290 to 350 deg. fahr. The course of the various parts is followed from the time of their receipt to that of their delivery to the assembling department to which they belong.

The Cadillac Company has used S.A.E. 3250 steel for at least 8 years. This is medium nickel-chromium steel. Many other kinds have also been tried. Experience has shown that transmission gears made of carburized steel are not within 30 per cent as accurate as those made of oil-treated steel. This may be because of the fact that more attention has been paid to oil-hardened than to carburized steel gears. Efforts to control the distortion of carburized gears were unsuccessful. The hardening was done in salt pots, lead pots and open furnaces, heated by gas, oil and electricity. The same thing applies to spur gears. Oil-treated steel for rear axles has not been tried. When transmission gears were made from drop-forged blanks made by the conventional pegged-out process from flat stock they became oval. Upset gear forgings are used as fast as the forging suppliers can become equipped for the work.

Graphical demonstration is given of the desirability of grinding gears that are made of carburized material. The warping of carburized gears is shown to be due to the shrinking of the carburized metal. The teeth cut on the regular commercial type of hobbing machine vary in form; those cut on a simplified hobbing machine are more accurate. Tooth forms made from oil-treated steel are much better than those made from carburized and hardened steel. The conclusion is that carburized gears must be ground, but when oil-treated and accurately cut on a simplified hobbing machine grinding may be necessary only when the teeth have become mutilated.

Supplementing a paper by another author that treats of the theoretical balancing of this engine, Mr. Anderson presents the practical methods that have been devised to accomplish the results desired. Since this crankshaft is not in running or in dynamic balance without its piston and its connecting-rod assemblies, it is necessary to apply equivalent weights on each of the crankpins when balancing it on a dynamic balancing-machine, and details are given of how these weights are determined. The selection of parts to obtain equal weights is also necessary; a description is given of how this is made. A combination static and dynamic balancing-machine that can be set for either operation is used for balancing the crankshaft. Details of its operation are presented. Service conditions to secure parts replacements within the weight limits specified are outlined, and flywheel, universal-joint assembly and other unit balancing is discussed. The method of testing the completed work is stated.

Remarking upon the progress made by the builders of machine-tools in providing equipment for locating and correcting the unbalance of rotating parts, the author divides into three major groups the units of a motor car that require particular attention and treatment to assure a smooth-running mechanism and gives details of the actual methods employed by the company he represents to balance the parts that constitute each group in the vehicles it produces. Representatives of the engineering and the manufacturing departments of this company studied the subject intensively and determined the types of balancing-machine and the methods to be employed, and special balancing equipment was devised also. Details of the balancing practice for crankshafts, flywheels, connecting-rods, clutches and propeller-shafts are presented and the subjects of impulse balance and the maintenance of balance for assemblies of parts are discussed.

References to previous theoretical discussions of engine balance are cited prior to consideration of vibrations in four, six or eight-cylinder engines that may either be felt or heard in the car and result from lack of balance. Dynamic arrangement of the engine, unequal forces set up by the unequal weights of moving parts and vibration arising from elasticity or yielding of the parts themselves are the major causes of unbalance, of which the unequal weights of the parts are within the manufacturer's control. Unbalance of the conventional four-cylinder engine is of considerable magnitude, due to the angularity of the connecting-rod that produces unequal piston motion at the upper and lower parts of the stroke, the unbalanced force reversing itself twice per revolution and acting in a vertical direction. The actual magnitude of this force varies directly with the weight of the reciprocating masses and as the square of the speed.

Very few data seem to be available on the frictional losses in automobile engines caused by the failure of the oil to perform its function as a lubricant. The researches of the Lubrication Inquiry Committee in England indicate that the friction of a flooded bearing is proportional to the speed of the engine, the area of the bearing and the viscosity of the lubricant and is independent of the pressure and of the materials of which the opposing surfaces are composed. The principal sources of friction in an engine are the crankshaft, the camshaft and the connecting-rod bearings, which rotate; the pistons and the valves, which slide; and the auxiliaries, such as the generator, the pump and the distributor.

A practical method of nickel-plating is outlined and the various processes are described by which the Packard Motor Car Co. has been successful in producing a durable coating of nickel on automobile parts in general, and the radiator shells, the rim plates and the tire-carrier plates, in particular. These are the parts of greatest exposure, and for plating them a new system of moving-cathode tanks was installed. The three problems to which special attention was devoted were rusting, pitting and peeling. No effort was made to secure a coating of any designated depth but reliance was placed solely on the results indicated by a 24-hr. salt-spray test, which was considered to be the equivalent of 2 years' exposure to the usual weather conditions. Peeling was overcome by thoroughly cleaning the parts before plating. New equipment was purchased and laid out in accordance with the system decided upon, namely, copper-plating, buffing and nickel-plating.

Describing how the total weight of an airship becomes less as its flight continues and how its elevators can be used to keep the airship's nose pointed downward, thus balancing the excess lift by “dynamic lift,” the author says that 5 hr. is about the limit of flight for which the too great lightness can be overcome in this fashion safely, explains how different the conditions become on long flights and gives details of the means used to counteract this rising tendency. Valving of gas to overcome airship lightness is wasteful and costly, especially when the craft is inflated with helium gas but, if this is not done, some substance must be collected and stored at the same rate as that at which fuel is consumed in the engines and the most practicable method seems to be to recover water from the exhaust gases.

Principal developments along the lines of the HS, H-16 and F-5-L types of seaplane, which were used during the war for convoy work, submarine patrol and scouting, are represented by present types PN-7, equipped with Wright T-2 engines, and PN-8, having Wright T-3 engines, a metal hull and metal tail-surfaces. Brief statements about their construction and performance are made and the subject of metal floats for seaplanes is discussed. “Training,” scouting and other types of seaplane are mentioned, and outlines given of their characteristics and performance. Launching airplanes from a catapult is described, some details of the development of the apparatus being given, and reference is made to a late development in which the catapult is actuated by the explosion of a powder charge instead of being operated by compressed air.

Referring to the McKeen gasoline-driven car and one of the gasoline-electric type that were introduced in the early part of the present century and were the pioneers among self-propelled cars for railroad use, the author ascribes their limited success to their excessive weight and to engine and transmission troubles. Both these types, he thinks, might have been developed successfully had the gasoline engine been in its present state of efficiency and reliability. The early attempts having been more or less unsuccessful, the construction of all types was discontinued during the war. More recently the progress in the design and construction of highway motor-trucks has caused them to be adapted to railroad service by applying flanged tires to the rear wheels, pivotal pony-trucks forward and a motorbus body for the carrying of passengers and a limited amount of baggage.

This paper is confined to a discussion of machine-shop operations, and is intended to indicate by a few examples certain important economies that might be introduced in the shops of the automotive industry. It deals chiefly with the economies that can be effected without much capital outlay, though others are also mentioned. Calling attention particularly to the fact that, in the past, improvements of methods and of equipment have been confined largely to the more important operations on the more important parts and that relatively little study has been made of the smaller pieces and the less important operations, emphasis is placed on the necessity for carefully determining which tools and which makes of tool will best serve the purposes for which they are intended and for carefully sharpening the tools and providing means of setting them accurately.

Gasoline rail-cars for branches of trunk-line railroads and for short-line roads have been the subject of much discussion since 1920. Mechanical officers of interested railroads, the engineers of companies building highway motor-trucks and others specializing on this subject have now developed designs to meet the different service requirements. Several hundred cars of various types have been built and are in service. The railroad with which the author is connected has in operation or on order 24 cars. Consideration of several principal factors of design is necessary if a selection is to result in obtaining equipment suitable for the particular service requirements of the carrier and if the knowledge accruing from the engineering development and operating experience of the past several years is to be of value.

Coining-press development is outlined and the author tells how such machinery was adapted to speed-up the production of automobile parts, such as forged arms and levers, by a squeezing process that superseded milling or spot-facing methods. The presses used are very rugged in construction and have the appearance of a plain-type punch-press, except for the knuckle that operates the ram. This knuckle is coupled to a crank by a connecting-rod or link. As the crank revolves, it straightens the knuckle. The pressure transmitted to the ram is many times greater than that which could be produced through a single-acting direct-connected crank-operated type of machine. An additional advantage of the knuckle movement is in the application of pressure at the end of the downward stroke. The position of the ram at the end of the stroke is controlled by a screw-actuated wedge.

Public thoroughfares have invariably been laid out to meet the requirements of age-old horse-and-buggy equipment and little thought has been given to the needs of the future. Until the middle of the last century, man was dependent for transportation upon his own strength or upon that of the animals that he could domesticate. Caesar could have traveled from Rome to Paris as quickly as could Napoleon 17 centuries later. Now, the humblest American farmer could make the round-trip with his whole family in less time than either emperor could travel one way. Within the last century have been developed in rapid succession the railroad train, the steamship, the electric trolley-car, the automobile, the motor truck, the tractor and the airplane. The most permanent thing we have is land; the very slowness and regularity with which buildings are replaced tend to make a route and the width in which it is established almost as permanent as the land of which it is a part.

Lack of scientific research is specified by the author as being the cause of failure to develop steering-systems generaly to meet the present need for better and easier steering-ability. He comments upon the meager data available regarding steering-system faults and factors that influence design and emphasizes the necessity for determining the live stresses in steering-systems while the vehicle is traveling over roads of all kinds, so that designs can be made with greater confidence and greater safety attained. Defining comfort as being inclusive of easy steering, a comfortable sitting position, convenient location of the controls that must be handled frequently and peace of mind relative to steering accuracy and dependability, he analyzes the causes of hard steering, saying that the steering-system includes every part from the steering wheel through the steering-gear and linkage to the front wheels and that the steering-gear itself is simply the reduction mechanism. Assisted by H. A.