CHAPTER XIII.

GENERAL ECONOMY OF STEAM POWER.

Mechanical efficacy of steam -- proportional to the quantity of

water evaporated, and to the fuel consumed. -- Independent of the

pressure. -- Its mechanical efficacy by condensation alone. -- By

condensation and expansion combined -- by direct pressure and

expansion -- by direct pressure and condensation -- by direct

pressure, condensation, and expansion. -- The power of engines.

-- The duty of engines. -- Meaning of horse power. -- To compute

the power of an engine. -- Of the power of boilers. -- The

structure of the grate-bars. -- Quantity of water and steam room.

-- Fire surface and flue surface. -- Dimensions of steam pipes.

-- Velocity of piston. -- Economy of fuel. -- Cornish duty

reports. 277

The Steam Engine Familiarly Explained and Illustrated With an historical sketch of its invention and progressive improvement; its applications to navigation and railways; with plain axioms for railway speculators · 第 13 / 19 章