74 FOEESTS, WOODS, AND TKEES 



Sheep-grazing is from the waterworks' point of view the least 

 objectionable of farming pursuits. Grouse moors are still less 

 objectionable, especially where the growth of peat is kept under 

 proper control and suitable channels are cut for the water." 



Sheep-grazing, though generally believed to be innocuous, 

 is not without danger, as frequently the sheep die, and 

 their dead bodies are found in the streams. In one 

 gathering ground, in order to encourage early notice, the 

 corporation offers 5s. each for the bodies of dead sheep 

 that may be found. J. W. Hill of Cincinnati, who built 

 many waterworks in the United States, criticised (3) severely 

 the Edinburgh Water Trust for permitting sheep -grazing 

 on the Talla watershed, and said it was a hazardous 

 experiment. He instanced the occurrence in Switzerland 

 and in the Rocky Mountains of epidemics of typhoid 

 fever, due to the water supply being contaminated by 

 cattle which grazed on the gathering ground. He objected 

 to any occupation of the catchment area of a watershed by 

 either man or animals. W. L. Strange (4) says : " All 

 surface catchments are liable to pollution, for even in 

 pastoral areas there is contamination from man, animals, 

 and vegetation, and filtration is therefore necessary. 

 Pathogenic germs multiply rapidly and one cannot depend 

 on their easy destruction. Silt in drinking water taken 

 from rivers in India gives rise to bowel complaints, due to 

 numerous minute flakes of mica in the silt." 



In the gathering grounds which supply water to New 

 York and Boston, U.S.A., there are numerous dwelling- 

 houses ; and the American engineer Hazen says it is 

 unnecessary to remove the population from a water catch- 

 ment area if suitable precautions are taken. Dr. A. C. 

 Houston writes to me in reference to this : " Hazen incurs 

 serious responsibilities by such a statement. Everything 

 turns on the perfected nature of the precautions, and 

 certainly as a counsel of perfection an uninhabited area 

 is most desirable. Still I am free to admit that by storage, 

 filtration (5), and sterilisation the most impure water can 

 be rendered safe for domestic use." The question of supply 



