Mechanics
MECHAN'ICS, noun That science which treats of the doctrines of motion. It investigates the forces by which bodies are kept either in equilibrium or in motion, and is accordingly divided into statics and dynamics.
A mathematical science which shows the effects of powers or moving forces, so far as they are applied to engines, and demonstrates the laws of motion.
It is a well known truth in mechanics that the actual and theoretical powers of a machine will never coincide.