STORAGE AND REGULATION OF WATER. LIX. 



Power might also be obtained by running water from the 

 river, down deep wells to the tertiary drifts for the purpose 

 of working turbines, whose power when transformed into 

 electrical energy could be used for pumping river water 

 for irrigation purposes. The horse power developed will 

 = *079 Q h, where Q is the quantity of water in cube feet 

 per second, and h is the fall in feet, so that if only one cubic 

 foot per second is taken from the river and allowed to 

 actuate a turbine at a depth of 120 feet, it will generate 

 almost 10 HP. This power after making all due allowance 

 for loss in conversion, will raise say 4 cubic feet per second 

 or 1,500 gallons per minute to a height of 20 feet. The 

 dynamo is to be worked direct by the turbine at the bottom 

 of the well and the power conveyed by wires to the river 

 bank. 



When water has been stored it should be delivered to the 

 consumers in measured quantities and with as little loss as 

 possible. The measurement may be made in two ways, 

 either by the use of meters or modules, the first of which 

 indicates how much has been used, whilst the second only 

 permits of a certain fixed quantity per minute to pass 

 through it. Meters are well known under the following 

 names : — Low pressure positive, in which all the pressure 

 in the pipes is lost, and the quantity of water passing 

 through them is actually measured. Inferential, in which 

 the amount of water is inferred from the velocity of its 

 flow, this velocity being measured by means of vanes. 

 Venturi meters, in which the velocity of the water is shown 

 by means of the height of water in a gauge. This is one 

 of the best form of meters for measuring large quantities 

 of water, as it has no working parts, and consequently no 

 friction. The principle upon which it works, was dis- 

 covered in 1797 by M. Venturi, who found that the flow of 

 water in a pipe, past its junction with another pipe, created 



