446 THE APPLIED SCIENCES, 



there is almost no one of the arts which it may not subserve. The 

 mechanical arts, the arts of construction, mining, and naviga- 

 tion, are all indebted to it. Every operation, in short, in which 

 motion is to be communicated according to fixed rules, and in a 

 settled order, must be capable of receiving that motion, which is its 

 life, from this universal agent. 



But let us turn to those operations in which this condition 

 does not hold, in which the ever- varying circumstances almost 

 preclude the employment of any agent but one endowed with free- 

 will or, at all events, one whose effects may be made to vary with 

 the ever-changing conditions, and we shall still find abundant 

 evidence of the debt which civilisation owes to the applications of 

 science. Let us look to the public works of England, and we shall 

 learn how much the spirit of free enterprise, leaning on the arm 

 of science, can accomplish. We may take on this subject the 

 testimony of an impartial and enlightened foreigner. Until the 

 year 1756, says M. Dupin, England did not possess a single line 

 of artificial navigation ; while her land communications were limi- 

 ted to a small number of. ill-planned and ill- constructed roads. 

 Then, for the first time, a private individual ventured upon an 

 outlay, which his bold speculations told him must eventually bring 

 a large return ; and he constructed a canal, which was to carry to 

 the town of Manchester the produce of his mines. Soon after, 

 Liverpool, seeking a freer passage for her commerce, formed and 

 realized the project of opening a navigable way between the Irish 

 channel and the German ocean. Other canals, more extended 

 still, were by degrees constructed ; and, in the short space of half 

 a century, a double system of canals has ramified itself throughout 

 Great Britain, exceeding three thousand miles in length. 



The roads of England, adds the same writer, are the subject of 

 yet vaster labours. The existing roads have been enlarged, and 

 constructed anew on better principles ; new roads have been opened 

 to commerce, and internal* intercourse ; and a network of lines of 

 land communication now exists in England alone, measuring 

 115,000 miles ! Meanwhile spacious harbours are formed to contain 

 her vessels ; piers, embankments and light-houses, augment the se- 

 curity of approach, and of shelter, over an extent of more than 1500 

 miles of coast ; and 22,000 merchant vessels, capable of carrying two 

 millions of tons of merchandize, and manned by 160,000 sailors, 

 are scarce sufficient for her commerce and her carrying trade. 



