The paper opens with a number of quotations from publications issued by the Army War College and showing the bearing of motor transport on a proper military policy for the United States. The author then describes two experimental trips recently made by motor-truck owners near New York in an effort to determine proper motor-transport operating conditions. A statistical summary is given for these two experimental trips. The Army War College has issued in compliance with instructions of the Secretary of War a “Statement of a Proper Military Policy for the United States,” supplemented by a number of pamphlets dealing with particular features of this military policy in considerable detail. In many of these supplementary pamphlets there appears a considerable amount of material bearing upon the subject of motor transport and from them the brief quotations in the following paragraphs are taken.
The author outlines the constructions that have performed cially that four-cylinder engines carried under a hood are the most satisfactory. The defects revealed by war service are given in considerable detail, the author finding that all of the trucks used had developed some weak point. Radiators and springs are specified as a general source of trouble. The author outlines a number of operating troubles developed under the existing conditions of operation and gives examples of the way these have been remedied. Considerable attention is paid to the methods of operating trucks away from made roads. The methods of fitting chains to the wheels, and the use of caterpillar attachments are described. Dimensions are given for bodies and a number of suggestions made as to their proper construction.
Inasmuch as horses cannot meet the demand for increased farm power, the tractor must come at once. So far the supply of tractors has been entirely inadequate to meet the demand. The author specifiies some of the problems that confront designers of farm tractors. To make the tractor immediately available for farm work, it must be adaptable to practically all of the existing types of horse-drawn implements, besides furnishing belt power for a wide variety of present power-driven farm machinery. In designing tractors it must be remembered that the horse is a very flexible unit, capable of a wide variation in power output. Designing a tractor to furnish the necessary power for the majority of farm conditions, requires an intimate knowledge of crops, soils and farm management. These must be analyzed carefully so as to make the machine have as wide a range of usefulness as possible.
The results are given of laboratory investigations made of a number of different types of carbureters, showing the relation between their gasoline and air consumptions over a wide range. This relation is plotted on so-called quality diagrams, on which is indicated the range between which high power and high efficiency can be expected. A description is given of a carbureter arranged in two stages, the first being used at light load and the second coming into action when the throttle is nearly open, thereby more than doubling the carbureter capacity. Engine performance curves are presented showing the result when only one or both stages of this carbureter are used.