INTRODUCTION.

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as Mr. Watt’s expression was assumedmore as a conventional standard for ahorse’s power, than the true measure ofthe energy which he is capable of exert-ing upon the load, perhaps those in theTable, being the result of long-continuedpractice, will be a more correct expres-sion of his energy.

In the case of loco-motive engines, asufficient number of Experiments aregiven, I trust, to elucidate both the lawswhich regulate their action, and, also, theextent of their performance and utilityin the conveyance of goods upon Rail-roads. The uncertainty which exists, ingeneral, respecting them, renders thisextremely necessary; and, if I have beentoo prolix in the elucidation of theirseveral modes of action, it has arisen from