The theory of the steam engine : showing the inaccuracy of the methods in use for calculating the effects or the proportions of steam-engines, and supplying a series of practical formulae to determine the velocity of any engine with a given load, the load for a stated velocity, the evaporation for desired effects... : with an appendix containing concise rules for persons not familiar with algebraic signs, and intended to render the use of the formulae...perfectly clear and easy