THE PHYSICAL CHARACTERISTICS OF ROAD AND FIELD DUST
In a study of the dust problem that has lasted more than 2 years, many observations, measurements and experiments were made to determine the nature and effect of dust and the best means for its elimination as a cause of engine wear. The results of these experiments, which seem to be of general interest, are reported and cover briefly such matters as the chemical composition of road dust, its particle size, specific gravity, and abrasive nature and the relative amounts of it to which an engine may be exposed under varied conditions. Curves are also submitted that show the average cylinder-wear on a number of test cars. The methods of testing air-cleaners are described, the principles underlying commercial air-cleaners are discussed and a list of what the author believes to be important elements of air-cleaners for passenger cars is given.