Both originally published in 1930 by Litton Educational Publishers. One of the earliest introductions to the subject. S.P. Timoshenko, History of Strength of Materials , Dover, 1983. Originally published by McGraw-Hill in 1953. A joy to read for those who have an interest in the origins of this subject.
Discussion goes well beyond the confines of the title.
Should be required reading for students. First edition 1949. Fourth edition 1970. P.M. Morse and K. U. Ingard, Theoretical Acoustics , Princeton University Press, Princeton, 1968. A very thorough introduction to the subject.