88 



A. Pedler— 



On ill e past and present 



[No. 2, 



the same water ; cooking water is used scantily, or more than once ; habi- 

 tations become dirty, streets are not cleaned, sewers become clogged ; and 

 in these various ways a want o£ water produces uncleanliness of the very 

 air itself. 



" The result of such a state of things is a general lowered state of health 

 among the population ; it has been thought also that some skin diseases — 

 scabies, and the epiphytic affections especially — and ophthalmia in some 

 cases, are thus propagated. It has also appeared to me that the remark- 

 able cessation of spotted typhus among the civilized and cleanly nations, is 

 in part owing, not merely to better ventilation, but to more frequent and 

 thorough washing of clothes. 



" The deficiency of water leading to insufficient cleansing of sewers has 

 a great effect on the spread of typhoid fever and of choleraic diarrhoea ; and 

 cases have been known in which outbreaks of the latter disease have been 

 arrested by a heavy fall of rain." 



In judging of the quantity of water necessary to be supplied to a town, 

 notice must be taken of the purposes for which the water is used. These 

 we may roughly summarise by saying that water is required for drinking, 

 cooking and the washing of persons, clothes, utensils and houses, for the 

 flushing and cleansing of sewers and drains and for the watering of streets, 

 for the drinking and washing of animals, the cleansing of carriages and 

 stables, for trade purposes, etc. 



From European statistics given by the authority just quoted, it would 

 appear to be generally admitted, that a fair allowance of water for the pui'- 

 poses above enumerated is 25 gallons per head of population per day. Thus 

 taking some of the largest towns in England and ^including Paris, each in- 

 habitant receives 27i gallons per day ; the average daily supply of 14 English 

 towns of second rate magnitude was 24 gallons per head, and that of 72 

 English and Scotch towns was found to be 26"7 gallons per inhabitant. 



Let us now see the amount of water available in Calcutta during cer- 

 tain portions of the year when the old supply was depended upon. The 

 tanks and wells in any town can of course only receive their supply of water 

 from rain, and the rainfall of Calcutta is so unequally distributed, that 

 almost three quarters of the whole fall takes place within 4 months of the 

 year, whilst within 6 months, ten-elevenths of the rain falls. Thus the 

 annual rainfall of Calcutta from 49 years' observation, has been found to be 

 6.5'85 inches, and dm-ing the months from November to April inclusive, 

 only 6 03 inches fall on the average. 



If we exclude from our calculation the months of heaviest rainfall, 

 when the water would almost entirely run off into the river and be 

 lost, and assuming for a moment that during these six months from Novem- 

 ber to April, the whole of the water which fell could be collected and 



