550 PRACTICE OF AGRICULTURE. Part III. 



Chap. V. 

 Of the Formation of Canals. 



3526. Though the subject of canals is not included in that of agriculture, yet it is so inti- 

 mately connected with territorial improvement, that it would be improper in a work of 

 this description to pass it over. Canals of any extent are never the work of an individual, 

 but of public bodies, constituted and empowered by public acts; but it is of importance 

 to individuals to know the sort of effect which a canal passing through their property may 

 have, both on its appearance and value ; not merely as a medium of conveyance, but as 

 a source of population, of water for irrigation or mills, or the use of stock, and even as 

 an object of ornament. For this purpose we shall submit some remarks on the utility of 

 canals, the choice of lines, the powers granted to canal companies, and the mode of 

 execution. 



Sect, I. Utility of Navigable Canals. 



3527. Good roads, canals, and navigable rivers, Dr. Smith observes ( Wealth of Nations, 

 i. 229), by diminishing the expense of carriage, put the remote parts of the country 

 more nearly upon a level with those in the neighborhood of large towns ; and on that 

 account they are the greatest of all improvements. They encourage the cultivation of the 

 remote parts, which must always be the most extensive circle of the country. They are 

 advantageous to towns, by breaking down the monopoly of the country in its neighbor- 

 hood, and they are advantageous to all parts of the country ; for though they introduce 

 some rival commodities into the old markets, they open many new markets to its produce. 

 *'A11 canals," says an intelligent writer on this subject (See Phillips's General History of 

 Inland Navigation, Introd. ) " may be considered as so many roads of a certain kind, on 

 which one horse will draw as much as thirty horses on ordinary turnpike roads, or on 

 which one man alone will transport as many goods as three men and eighteen horses usually 

 do on common roads. The public would be great gainers were they to lay out upon the 

 making of every mile of a canal twenty times as much as they expend upon a mile of turn- 

 pike road ; but a mile of canal is often made at a less expense than the mile of turnpike; 

 consequently there is a great inducement to multiply the number of canals." 



3528. General arguments in favor of canals are superseded by the rapidly improving 

 and thriving state of the several cities, towns, and villages, and the agriculture also near 

 to most of the canals of the kingdom, the immense number of mines of coal, iron, lime- 

 stone, &c. and great works of every kind to which they have been conducted, and to 

 which a large portion of them owe their rise, are their best recommendation. In short, 

 it may be concluded, that no canal can be completed and brought into use, but the in- 

 habitants and the agriculture of the district will shortly feel great benefit from it, whatever 

 may be the result to the proprietors, 



3529. The great advantages of canals as means of transport results from the weight 

 which may be moved along by a small power. The velocity with which boats can be 

 drawn along a canal is confined within very narrow limits, owing, as Edgeworth has ob- 

 served, to the nature of the resistance to which they are exposed; this resistance increasing 

 in a geometrical proportion, as the squares of the velocity with which the moving body 

 is impelled. Whereas on roads or railways, an increase of velocity requires only an 

 arithmetical increase of power; or, in other words, to draw a boat with ten times a given 

 velocity, would require a hundred times as much power as was requisite to draw it with 

 that given velocity. Whereas, to draw a carriage on a road or railway with ten times 

 a given velocity, would require only ten times the given power. For this reason, how- 

 ever advantageous canals may have been found, for transporting heavy loads, they will be 

 found upon trial inferior to roads in promoting expedition. 



3530. Canals appear to have been first made in Egypt. Though less attended to by the 

 Romans than roads, yet they formed some in this country near Lincoln and Peterbo- 

 rough. China is remarkable for its canals, and there are many in Hindostan. In Rus- 

 sia there are some and especially in Sweden ; one or two in Denmark ; some in Germany, 

 and a great many in Holland. The canal of Burgundy in France was commenced un- 

 der Henry IV. and that of Languedoc finished by Riquet, the Brindley of France, under 

 Louis XIV. Some attempts have been made to form canals in the hilly country of 

 Spain, and a great many excellent ones are executed in America. 



3531. Navigable canals in Britain took their rise between 1755 and 1760, by the San- 

 key Brook Company in Lancashire; but the great impulse was given by the duke of 

 Bridgewater about 1 757 ; when he first commenced, under the direction of Brindley, the 

 canal between his coal-works at Worsley and Salford. The duke of Bridgewater has, 

 in consequence, not improperly been called the father of canals in England; while his 

 engineer, Brindley, by his masterly performances on the duke of Bridgewater's canal, 

 altered and extended as the scheme thereof was by the three subsequent acts of parlia- 



