THE STEAM-ENGINE. INTRODUCTION. 1. THE STEAM-ENGINE is a machine for the production of motion, in which steam (the vapour of boiling water) is used. A MACHINE (from the Greek mechané, through the Latin machina) in the sense now generally understood, means a contrivance for applying to some object a continuous and regular motion, as a spinning wheel, a loom, a watch or clock. If we choose to extend the term so as to include such contrivances as a gun, a mortar, a bow and arrow, a sling, we must at all events carefully distinguish between those which give a continuous and regulated movement, and those which only impart a sudden, irregular, and quickly terminated impulse. The Steam-Engine is a sort of primary machine, the object of which is the production of force, or moving power, by means of which continuous motion may be communicated to other bodies-as the wheels of a carriage; paddles or oars for propelling vessels on water; the rod of a B |