SECRETARY'S REPORT. 251 



at the level of the clam. Kunning water i.s never level, or it could not 

 flow ; and in crooked streams which How through meadows, obstructed 

 by grass and bushes, the water raised by a dam, often stands many feet 

 higher, at a mile or two buck, than at tlie dam. It is extremely difficult 

 to set limits to the effect of such a flowage. Water is flowed into the 

 subsoil, or rather is prevented from running out ; the natural drainage 

 of the country is prevented ; and land which might well be drained 

 artificially, were the stream not obstructed, is found to lie so near the 

 level, as to be deprived of the requisite fall by back water, or the 

 sluggish current occasioned by the dam. 



These obstructions to drainage have become subjects of much atten- 

 tion, and of legislative intervention in various forms in England, and 

 some of the facts elicited in their investigations are very instructive. 



In a discussion before the Society of Arts, in 1855, in which many 

 gentlemen, experienced in drainage, took a part, this subject of obstruc- 

 tion by mill-dams came up. 



Mr. G. Donaldson said he had been much engaged in works of land- 

 drainage, and that, in many instances, great difficulties wei-e experi- 

 enced in obtaining outfalls, owing to the water-rights, on the course of 

 rivers for mill-power, &c. 



Mr. R. Grantham spoke of the necessity of further legislation, " so as 

 to give power to lower bridges and culverts, under public roads, and 

 straighten and deepen rivers and streams." But, he said, authority was 

 wanting, above all, " for the removal of mills, dams, and other obstruc- 

 tions in rivers, which, in many cases, did incalculable injury, many 

 times exceeding the value of the mills, by keeping up the level of 

 rivers, and rendering it totally impossible to drain the adjoining lands." 



Mr. R. F. Davis said, " If they were to go into the midland districts, 

 they would see great injury done, from damming the water for mills." 



In Scotland, the same difficulty has arisen. " In many parts of this 

 country," says a Scottish writer, " small lochs (lakes) and dams are kept 

 up, for the sake of mills, under old tenures, which, if drained, the land 

 gained by that operation, would, in many instances, be worth ten times 

 the rent of such mills." 



In the case of the Rye and Derwent Drainage, an account of which 

 is found in the 14th volume of the Journal of the Royal Agricultural 

 Society, a plan of compensation was adopted, where it became necessary 

 to remove dams and other obstructions, which is worthy of attention. 

 The commissioners under the Act of 1840, removed the mill-wheels, 

 and substituted steam-engines corresponding to the power actually used 

 by the mills, compensating, afco, the proprietors "for inconvenience, and 

 the future additional expensiveness of the new power. 



