This treatise on rigid-frame analysis is a compilation of a series of 44 articles by the author, previously having appeared as technical supplements to the U. S. Navy Bureau of Yards and Docks News Memorandum. These articles were written primarily for the benefit of the Bureau's technical personnel, as an aid in the design of continuous structures. The book was originally published in 1942, when conservation of all structural materials was a paramount necessity, and the importance of modern methods of analysis, as a means of realizing appreciable savings in materials was critical.