USE OF SPRINGS. 113 



influence of the atmosphere, may be as thorough as pos- 

 sible. 



The temperature of the water has a considerable effect 

 upon the growth of grass. Every one has noticed the 

 effect of a warm shower, in early Spring, in starting vege- 

 tation ; and also the ill effect of a cold rain, in the Fall, in 

 arresting growth. In all cases the water should at least 

 be of an equal temperature with the air. When spring 

 water is used, the temperature can only be raised by ex- 

 posing it in ponds or reservoirs for a time, and the shal- 

 lower the pond the more quickly will the water be warm- 

 ed. Exposure to the atmosphere also exerts a chemical 

 effect, and some waters that contain sulphate of iron, or 

 other deleterious substances, are rendered harmless by 

 the oxidation of these impurities. Thus the temporary 

 storage is of sufficient advantage both in enabling an in- 

 termittent irrigation, and in warming and purifying the 

 spring water, to make the cost of the reservoir and dis- 

 tributing apparatus a profitable expenditure for any 

 meadow of not less than four acres in extent. 



It is often the case that a number of springs exist upon 

 the surface that may be brought 

 together into one channel with 

 great economy. A spring is often 

 merely the overflow of under- 

 ground streams, and by digging 

 downwards the whole of the water 

 may be captured and brought into 

 one channel, with the double ad- Fi g- 48. THE DRAIN AND 

 vantage of draining a wet field MBOHABGB PIPE. 

 and of utilizing the water for the irrigation of a meadow 

 below the level of it. The diagram, fig. 47, represents 

 a case of this character. A number of springs break out 

 at the surface, and spreading make a marsh, but form 

 no stream there. To utilize the water of these springs, 

 and to drain the wet surface, all that is needed is to 



