Originally published in 1912, this book presents the result of various experiments performed between 1908 and 1909 into the wind currents in the air above the surface layers of our atmosphere. Cave rigorously details the background to each experiment, which were done with pilot balloons tracked with a theodolite, and makes meteorological drawings based on the findings of each experiment. This book will be of value to anyone with an interest in meteorological history and the methodology of meteorological experiments before computers.