Every man who runs a traction engine ought to know something of the magnitude of the force he is working with. He ought to know something about the strength of materials in his boiler and engine. He ought to know the exact construction of every part of his machine. He ought to know how to make all the necessary repairs and make all necessary adjustments and he ought to be familiar with the scientific laws governing every operation of an engine or any of its parts.
Steam Engine Guide, by Professor P.S. Rose