OF NATURAL PHILOSOPHY. 59 



(4-8.) We have hitherto considered only cases in 

 which a knowledge of natural laws enables us to im- 

 prove our condition, by counteracting evils of which, 

 but for its possession, we must have remained forever 

 the helpless victims. Let us now take a similar view 

 of those in which we are enabled to call in nature 

 as an auxiliary to augment our actual power, and 

 capacitate us for undertakings, which without such 

 aid might seem to be hopeless. Now, to this end, it 

 is necessary that we should form a just conception 

 of what those hidden powers of nature are, which 

 we can at pleasure call into action ; how far they 

 transcend the measure of human force, and set at 

 naught the efforts not only of individuals but of 

 whole nations of men. 



(49.) It is well known to modern engineers, that 

 there is virtue in a bushel of coals properly con- 

 sumed, to raise seventy millions of pounds weight a 

 foot high. This is actually the average effect of an 

 engine at this moment working in Cornwall.* Let 

 us pause a moment, and consider what this is 

 equivalent to in matters of practice. 



(50.) The ascent of Mont Blanc from the valley of 

 Chamouni is considered, and with justice, as the 

 most toilsome feat that a strong man can execute in 

 two days. The combustion of two pounds of coal 

 would place him on the summit, f 



* The engine at Huel Towan. See Mr. Kenwood's State- 

 ment " of the performance of steam-engines in Cornwall for 

 April, May, and June, 1829." Brewster's Journal, Oct. 1829. 

 The highest monthly average of this engine extends to 79 

 millions of pounds. 



f However, this is not quite a fair statement ; a man's daily 



