"How To Build A 20-Foot Bi-Plane Glider" by Alfred Powell Morgan is a practical handbook on aviation construction written in the early 20th century. This book serves as a guide for amateur builders interested in constructing their own biplane glider, providing comprehensive insights into the principles of flight as well as step-by-step instructions for assembly. The author aims to inspire curiosity and experimentation in the burgeoning field of aviation, following the pioneering efforts of earlier aeronauts. The book is structured in a clear and informative manner, starting with the necessary materials and framework design for the glider, emphasizing the importance of using specific woods and materials for optimal construction. Morgan explains the design elements needed for a stable gliding machine, including the coverings of the planes, trussing for stability, and the mechanics of gliding itself. Safety is a recurrent theme throughout, as he advises cautious experimentation and understanding of aerodynamic principles. Additionally, the book concludes with practical remarks and further reading suggestions for those keen on delving deeper into the science of aeronautics, making it an invaluable resource for aspiring aviators. (This is an automatically generated summary.)