1 62 The Drainage of Fens and Low Lands. 



TABLE V. 



To find the cubic feet of water to be discharged by a drain or 

 pumpi?ig ejtgine per mifiute due to any given quantity of rain falling in 

 24 hours ^ and the ho7'se-power ifi water raised for each foot of lift^ 

 multiply the number of acres drained by the multiplier opposite the 

 rainfall. 



Rain in 24 Hours. 



In parts of 

 Inches. 



Decimal 

 Equivalents. 



■125 

 ■250 



'375 

 •500 



•625 



750 



■875 



Multiplier for 



Cutic Feet per 



Minute per Acre. 



0*3151 

 0*6303 



0*9453 

 I '2606 



i'575S 

 1*8909 



2 * 2060 



2*5210 



Multiplier for 

 W.H.P. per Foot 

 of Lift per Acre. 



•000597 



•001 194 

 •001790 

 •002387 

 ' 002985 

 •003581 

 •004178 



•004775 



Example, — To find the quantity to be discharged per minute from 

 an area of 10,000 acres with a rainfall of a quarter of an inch in 

 24 hours ; and lift of s feet :- 



10,000 X 0*6303 = 6303 cubic feet. 



10,000 X 0-001194 X 5 = 59*70 water horse-power. 



Rai7ifalL 



I 



inch 



rain 



=: 



3 



,630 



cubic feet 



per acre 





>j 



J) 



= 





loi- 



183 tons 



j> 





j> 



>> 





122 



,614 



' 90 gallons 



n 



TABLE VL 



To find the discharge of water through sluices. 



Multiply the area of the waterway, or the space occupied by the 

 water, by the velocity as found in Table III. 



In calculating the area of the water passing through the sluice, the 

 depth must be taken at the lower side of the opening, as the velocity 



