1902. 



FORESTRY AND IRRIGATION. 



289 



-supply in natural or arti- 

 ficial reservoirs, either of 

 which collects the drain- 

 age water from a consider- 

 able area surrounding it, 

 or from a brook or river. 

 Seldom a year passes when 

 some contagious disease 

 does not spread through 

 towns or cities as a result 

 of impure drinking water. 

 Frequently the reser\'oirs 

 become dry owing to the 

 uneven flow of the streams 

 upon which the}' depend. 

 These streams, having bare 

 -watersheds, flow in tor- 

 rents in the spring, and 

 much of the water is 

 wasted. Later in the sea- 

 ;Son they run dry, and the 

 small pools formed in their 

 basins become stagnant. 



To these stagnant pools 

 the germs of disease have 

 free access and in them find 

 the conditions for devel- 

 opment. After the first 

 heavy rain they are washed 

 into the reservoir below, 

 sometimes contaminating 

 the entire water supply of 

 large cities. 



The planting of forest 

 trees on watersheds has not 

 been much practiced as yet, 

 but the necessity for it is 

 attracting the attention of 

 some of the most prominent water com- 

 panies in America. All pastures and 

 bare lands on such watersheds should 

 be covered with forest trees, and, 

 whenever natural reproduction cannot 



PI^ANTED WHITE AXD RED PINES, NEW HAMPSHIRE. TREES 



IN THE FOREGROUND HAVE BEEN ATTACKED BY THE 



WHITE PINE WEEVIL, EFFECT OF WHICH IS SHOWN 



IN THE DOUBLE LEADERS. 



ing effect, conversion of the watershed 

 lands into a beautiful park, and event- 

 ually practical lumbering at a profit on 

 the whole investment. 



An example of practical watershed 

 be depended upon, planting should be planting on a large scale may be found 



resorted to, with the ultimate purpose 

 of lumbering. Figures can now be 

 produced which show that planting 

 may be practiced without loss. It 

 therefore becomes a problem which 

 should be carefully considered by every 

 water company having waste or idle 

 lands. The effects of an evenly distrib- 

 uted forest on the watersheds are as fol- 

 lows : purification of the water, regu- 

 lation of the flow, prevention of erosion, 

 and hence of turbidity, cooling and shad- 



at Clinton, Mass., w^herethe Metropoli- 

 tan Water Board, which supplies Boston 

 and many surrounding cities with water, 

 is planting i ,500 acres in White Pine and 

 Hard Maple, according to plans prepared 

 by the Bureau of Forestry. Planting is 

 being done on the old farms, pastures, 

 and bare, waste lands upon the watershed 

 of their immense reservoir. Areas which 

 already contain forest trees wall be man- 

 aged with the idea of producing a crop 

 of timber from this natural growth. 



