Commander Read, who made the first transatlantic flight, writes on this subject: “There are some pilots with whom I would refuse to risk my life. But, given a modern machine with the proper attention paid it, and a skillful but conservative flyer, it is as safe a means of rapid transit as an automobile traveling at less than half the speed. Nowadays there is scarcely ever an accident in an aeroplane of standard type due to the fault of material; they are all due to the inexperience or to the dare-devil stunting proclivities of the pilot--the pilot who ‘takes chances.’” Aeronautics is now more than an art. It is a rapidly expanding branch of applied science. Aeronautical engineering has become one of the recognized professions. Some of the leading government laboratories of the world, including the National Physical Laboratory in Great Britain and the United States Bureau of Standards, are devoting their attention to aeronautical research. There are also many unofficial “aerodynamical” laboratories for studying, with the aid of wind tunnels and other apparatus, the many problems pertaining to the physics of flight and the principles of aeroplane designing. Aeronautical questions have begun to figure conspicuously in jurisprudence. Legislators, as somebody has said, are busy making vertical laws to supplement the old-fashioned horizontal ones. In international law, especially, aerial navigation has given rise to thorny problems and it is already the subject of elaborate international agreements. The physiological effects of flight and altitude have added a new chapter to the science of medicine. Seasickness has been the crux of the ship’s doctor; will “air sickness” prove equally baffling? What are the therapeutic possibilities of flying? Will physicians advise their patients to seek a “change of air” vertically instead of horizontally? The atmosphere, once monopolized by the birds, has become the abode of man. That is one excellent reason why everybody should acquire a knowledge of meteorology--the science of the air. CHAPTER IV DUST AND SMOKE IN THE ATMOSPHERE When the moralist reminds us that we are children of the dust and predestined to a dusty end, there is a grain of comfort in the discovery that modern science regards dust as one of the most important things in the whole economy of nature. No longer does dust seem an appropriate symbol of insignificance and humility when one surveys the bulk of serious literature that has been written about it, considers the caliber of the men who have devoted the better part of their lives to the study of it, or inspects the great array of ingenious apparatus that has been devised for its investigation.