Water-Rating. 429 



(b) Unobserved waste, such as is caused by faulty ball-cocks 

 which allow cisterns to overflow, or burst pipes, from which the water 

 escapes into the ground. 



True w^aste does not include unrestricted use, such as two baths 

 a day, scrubbing down the stoep, watering the streets, flushing 

 sewers, etc. These sometimes consume a large quantity of water, and 

 in the case of supply by meter would possibly be reduced, but they 

 are not waste. Waste is the item to be cut down, and though the 

 deliberate waste sometimes appears large, it is generally small com- 

 pared with the unobserved waste. It is estimated that at least 60 

 per cent, of the waste is unobserved, and one-half of that passes 

 through burst pipes. Consequently it seems to be false economy to 

 take much trouble over the deliberate waste, if the unobserved waste 

 is being neglected, and it is an unsound principle to restrict the use 

 before checking the waste. Domestic meters will soon draw attention 

 to the faulty ball-cocks and leaks on the consumer's pipes, but they 

 cannot detect burst mains. It is only by a proper system of inspec- 

 tion that these can be found. With waste detecting district meters 

 and night and day inspection, all waste can be discovered. All 

 waste cannot be stopped. It is found that very soon after a district 

 has been overhauled and put into first-class order, other sources of 

 leakage occur, and it is only by constant supervision that the 

 unobserved waste can be kept in check. 



It is not within the province of this paper to describe waste- 

 detecting processes in detail, but it may be of interest to observe that 

 by means of meters — waste-detecting district meters, not consumers' 

 meters — the cost of the work is greatly reduced. These meters shew 

 on a diagram (Figure 6) the rate of flow day and night. If there is 

 no unobserved waste, the night flow drops to nil. The day flow 

 may be high, indicating unrestricted use, even when there is a low 

 night flow, but a high night flow points to the necessity of bringing 

 the night inspectors round with their stop keys and stethoscopes to 

 show where the water is escaping. The day inspectors then go to 

 the spot indicated, and opening the ground, disclose the fault. The 

 night line indicates waste and this waste continues throughout the 

 24 hours. Its quantity can be estimated on the diagram, and com- 

 pared with the quantity used as shown by the day line (see Figure 7). 



Waste Inspectors can show all the unobserved waste that the 

 consumers' meters fail to show, and they do not wait until the 

 account comes in at the end of the month or the end of the quarter 

 before pointing it out. They do nothing to restrict the use of 

 water, and consequently are in no way antagonistic to sanitarians. 



Cost of iSIetering. 



Like most engineering questions, this ultimately comes to be one 

 of ;^ s. d. Is it cheaper for the consumer to spend money on meters, 

 which induce himself and neighbours to use water sparingly and to 

 prevent waste, or to spend the money on waste inspection and extra 



