16-

introduction.

on the various species of motive-power usedon Rail-roads, divided into four parts, viz.

Self-acting Planes,

Fixed Steam-engine Planes,

Horses , and

Loco-motive Steam-engines.

In Self-acting Planes the moving powerbeing the force of gravity, the action ofwhich is well-known, and that action

I

being communicated to the carriages bythe medium of ropes; a practical theoremis given, founded on the friction of ropes,as ascertained by Experiment .

The effective performance of fixedsteam-engines is, also, illustrated by fourexamples of engines dragging carriagesup ascents on Rail-roads, from whencewill be derived a rule for practical appli-cation .