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MOTIVE POWER EMPLOYED

IV —LOCO MOTIVE ENGINES.

In my investigations respecting loco-motiveengines, I shall confine myself wholly to thosewhich effect their progressive motion by meansof the adhesion of their wheels upon the rails ;the only engines of that kind at present inuse which do not, are those of Mr. Blen-kinsops, at Leeds, with the rack-rail; and asI have not had any opportunity of ascertain-ing their performance by the test of experi-ment; I shall not, therefore, attempt to giveany opinion of their utility, compared withthe other, founded only on report or on baresupposition.

I have before explained the nature of theaction of the engine-wheels upon the rails;and the principle by which the loco-motion iseffected; the great importance of knowing theproviso amount of that adhesion, whereby wemay be able to calculate, with certainty, uponwhat inclination of road, and with what num-ber of carriages, the engines can effect theirprogressive motion, will be very evident, as,upon that, the whole system of their actionis regulated.

This may either be ascertained by con-tinued observation of their performance upon