"Natural Stability and the Parachute Principle in Aeroplanes" by W. LeMaitre is a scientific publication written in the early 20th century. This book delves into the theories of stability in aeronautics, proposing methods to enhance the safety and effectiveness of aircraft design by focusing on natural stability rather than mechanical controls. LeMaitre's investigations are rooted in practical experiments and observations, aiming to provide insights that could lead to safer flying machines. The content of the book discusses various aspects of aeroplane design that contribute to stability, such as the importance of a low center of gravity, the effects of speed on stability, and the advantages of a shorter wing span. LeMaitre explores the concept of designing machines that can naturally return to a stable position without reliance on complex controls. Through detailed illustrations and theoretical explanations, the author emphasizes the significance of crafting a machine that can glide safely without engine power, akin to a parachute effect. His designs and theories are supported by experimental models, showcasing a vision for safer and more reliable aeroplanes that prioritize stability in their construction. (This is an automatically generated summary.)