The importance of the science of aerology is increasing steadily with the advance of aviation, of agriculture, and so on. The interest is widespread, if one can judge by the universality of weather reports (newspapers, radio, etc.). This is in small part a record of personal experience in high altitude flying, but primarily a study of the tremendous advance made in instruments, in theory of meteorology, in application of advance data. A chapter on amateurs, on weather in the air, and on the water. Some ventures in prophecy.