Papin, Denis, his contrivance, by which atmospheric pressure is rendered available as a mechanical agent, [48].
Description of his steam engine, [71]
Parallel motion, description of the, [95]
Piston, its velocity, [302]
Post-office steam packets, their speed, [268]
Potter, Humphrey, his contrivance for working the valves, [67]
Power of a steam engine, how estimated, [291]
R.
Railroads, first introduction of locomotives on, [151].
Important effects to be expected from their adoption, [155].
Imaginary difficulty respecting the progression of carriages on, [160].
Various methods resorted to, to remedy this supposed difficulty, [161].
One of these methods described, [162].
Comparative estimate of the expenses of locomotive and stationary engines, [168].
Difficulties arising from changes of level, [192].
Their great extension, [206].
Comparison of, with turnpike roads, [213].
Inclined planes on, [194]
Railway speculators, plain rules for, [307]
Roads, their resistance to draft, [213].
Compared with railroads, [213]