No. 244.] 181 



consumption of combustible exactly proportioned to the quantity of 

 work, and regulated the supply of fuel necessary to its own action. 

 It was also fondly believed that it was sufficient to provide for its own 

 safety from all danger. Painful experience has shown that the last 

 desideratum was not accomplished, and although engines are still in 

 habitual use in which all the other qualities are fully exhibited, some 

 of them are now sacrificed in those of modern construction, to the at- 

 tainment of others admitted to be of more importance. We would 

 refer more particularly to that most important change in the manner 

 of using the condensing engine by which it is set in action by steam 

 of high pressure, which is cut off before the cylinder is filled, and 

 thus permitted to act by its expansive force instead of its simple 

 pressure. In this mode the duty of a given engine is increased near- 

 ly five fold, and this even with a saving of fuel. In this way also 

 has the speed of our steamboats been increased to more than twice 

 that which theorists assigned as the limit of their velocity. To attain 

 these advantages, the original self-acting feeding apparatus has been 

 laid aside, and although many substitutes have been prepared and 

 even successfully applied, none of them have come into general use. 

 With this mode of using steam, by which its power is so much ex- 

 tended, the illustration of the progress of the engine ceases, and the 

 intent of the present lecture is accomplished. 



The great body of this audience has been familiar with the name 

 of the steam engine from infancy, and has been in the habit of wit- 

 nessing some of its most important applications from the earliest age. 

 But there may be those present, who with him who addresses, first 

 heard its name associated with the ridicule cast upon Livingston and 

 Stevens for fancying it capable of taking a vessel to Albany, and 

 who if they wished to see a steam engine in successful operation 

 must have taken a journey to Philadelphia, then the labor of two 

 days. The latter portion of my hearers will feel with me, that the 

 applications of the steam engine which have been developed under 

 ■our own eyes, constitute a series of triumphs of human ingenuity, 

 surpassing all that the imagination of poets could conceive, and re- 

 alising the wildest dreams of fiction. The history of the steam en- 

 gine in fact passes from the regions of mechanical plodding to those 

 of the imagination. The faculty is the same whether it be devoted 

 to the discovery of brilliant mechanical combinations or the elabora- 

 tion of poetical imagery ; the inventions of the mebhanicians of the 



