46 



WATERING THE PARKS. 



great advantage, namely, that it does not interfere in any 

 way with the circulation, and maintains the pathways clear 

 of dust or mud, while of course in places where there is no 

 grass to be watei^d the whole of the cost of water-pipes and 

 hydrants would be saved. 



The surface of grass which has to be watered with Seine 

 water in the Bois de Boulogne is about 250 acres, and the 

 quantity of water requii^ed to keep it in good condition 

 averages ten litres, or more than two gallons, per square 

 metre, every third day. To water this surface in the same 

 manner as the roads would require more than a hundred 



Fig. 21. 



Hose allowed to play on tlie grass and shifted from time to time. 



hose working ten hours a day, and this would entail a very 

 heavy cost. But as the grass does not require to be treated 

 with the same regularity as the roads one system adopted is 

 to place a branch on a stand at an angle of 45 deg., and 

 allow it to play over the grass for a certain time, when it is 

 removed to another spot : in this way one man can manage 

 ten apparatus. 



The total amount of water taken from the Seine for the 

 purposes of the Bois never exceeds 240 litres, or about 

 fifty-four gallons, per second. The natural meadows by the 

 side of the Seine form about 400 acres, but the soil here is 



