Charles Laboulaye (1813-1896) was a French engineer, known for his work on applied mechanics. His Traité de cinématique théorique et pratique ou Théorie des mécanismes (Treatise on Theoretical and Practical Kinematics or Theory of Mechanisms) is a fundamental textbook for the study of kinematics, the branch of mechanics that describes the motion of bodies without considering the forces that produce them. It was an essential resource for students and professionals interested in the design and analysis of mechanisms.