This average is greater than that of the entire city for the year 1888, but the fact is readily accounted for when we consider that the Minetta Brook Drainage District was occupied as a residential quarter, and, in addition, had a large floating shopping population whose needs would increase the total consumption and, not being enumerated, would bring up the average. In Diagram VI. the fluctuations of the sewage flow in 1888 and Mr. Freeman's observed fluctuations of surface in the Central Park reservoirs in 1899 are plotted to the same scale, and develop a remarkable similarity in their comparative relations, bearing in mind that, as suggested by Mr. Hering, the Central Park curve gives the flow several miles above the Minetta Brook gauge station, and that the two curves must, therefore, not be compared according to actual time, but with due allowance for the time required for the water to reach the lower end of the sewer from the reservoir. VI. ANALYSIS OF THE WASTE IN NEW YORK: CONCLUSIONS REGARDING ITS POSSIBLE PREVENTION. I have been furnished with a copy of the record of observations made under the direction of Mr. J. J. Croes, M. Am. Soc. C. E., for your committee in the present year, of twenty-five meters placed on residences in Manhattan for the purpose of determining average consumption. If this record be studied with a view to arriving at the present average consumption, it shows a result of 84.8 gallons per head per day. Throwing out the five cases which bear unmistakable evidence of being abnormally high (their average being 200.6 gallons per head per day), the average of the remaining twenty cases is 55.84 gallons per head per day, this being domestic consumption. But if we study the record with a view to getting the probable waste, we shall find that the average consumption in nine of the houses was only 42.8 gallons per head per day, while in the remaining 11 cases it was 66.43 gallons per head per day. As all were unrestricted, the fair conclusion is that the first set of households were more careful in their use of water than the second, and further that they might have gotten along with even less water than was used had they been obliged to pay for what they wasted. But assuming that the 42.8 gallons combines only actual and necessary use with incurable waste, for the class of inhabitants which this group represents, a class living in small families in separate establishments with ample facilities for bathing, etc., and considering the far greater numbers of inhabitants who live in congested condition without adequate facilities or opportunities for bathing frequently, the conclusion is unavoidable that the figure is far too high for an average of all. The average number of people, per residence, in the nine houses of lowest consumption, as above, is less than seven; while the average per building throughout Manhattan and the Bronx is nearly twice that. Mr. Croes, in his report, has estimated the waste in these 25 houses at nearly 50 per cent. of the water which passes through them. The average of the 25 being 84.8, 50 per cent. would make the waste 42.4 gallons per head per day. Deducting from the 84.8 of consumption the 42.8 used in the 9 houses, on the average which I have assumed to be normal use, the waste as I make it is 42 gallons per head per day, agreeing almost exactly with Mr. Croes. This element of the waste applies to the item of domestic use; there are likewise elements of waste in the items of trade and public uses. Taking the proportions I have assigned, viz., 30, 20 and 5, and assuming the elements of waste to be proportional thereto, then the total waste, both the preventable and the incurable, would be X42=77 gallons per head per day. Incurable Waste. Subtracting the figure which we have taken for the preventable waste (62 gallons) we have 15 gallons per head per day for the present incurable waste. Mr. Dexter Brackett, in the paper before quoted, expresses the opinion that it is not practicable to reduce the incurable waste below 15 gallons per head per day throughout a large city. Assuming the total waste thus found to be constant through the 24 hours, and applying Mr. Freeman's gaugings as exhibited upon his diagram hereinbefore referred to, we find that the ratio of night consumption to day consumption is 36.6 per cent.: Average Day Consumption (6 a. M. to 9 P. M.).. Actual Day Use, 125-77=... Ratio of Night Use to Day Use, 39.6 Per Cent. Preventable Waste. In conclusion, and in view of the array of facts presented, we are fully justified in the opinion that the present total theoretical preventable waste of that part of the New York water supply that is derived from the Croton system amounts to at least 120,000,000 gallons per day. Diagram VII. shows this graphically. The above amount of waste is the combined result of leaks in the reservoirs, leaks in the mains and distribution system, and defective house fittings and plumbing. I have made no attempt herein to separate the several elements. It may be considered that the reservoir leakage is so small as to be practically negligible. The experience of other communities which has been cited demonstrates very clearly that all the wastage might be attributed to defective plumbing, etc., without exceeding the reasonable probabilities, but there is probably considerable leakage in the mains and the distribution system also. The amount of theoretically preventable waste, as has been stated above, is about 53 per cent. of the total quantity of water delivered at the present time. The extent to which the prevention can be carried depends upon other considerations than physical laws, and can only be estimated. Under the assumption that the entire consumption be metered, I should be inclined to estimate the possible saving as a very considerable part of the theoretical amount, dependent upon the thoroughness of official action and the proper education of the public, for every householder would thereupon become directly interested in the reduction of the waste, and the inherent trait of human nature which previously had led him to consider that the more water he used the more value he was getting back from his taxes, would not cause him to feel concerned lest he should suffer by being made to pay for water he did not use. That is the experience in other places where meters have been universally applied, and to a greater or less extent is to be counted upon. Respectfully submitted, April 11, 1900. FOSTER CROWELL, TABLE 1. AVERAGE DAILY METERED CONSUMPTION: MANHATTAN AND THE BRONX. IN GALLONS. 1880. 1881. 1882. 1883. 1884. 1885. 1886. 1887. 1888. 1889. 1890. 1891. 1892. Year. 2.6 River- 2.0|49,980 .25 1.8 9,830,680 991,006|10.0 8,515,584 86.6|315,588 3.2 8,502 .09 1.764,306 .20 1.780,320 .30 1.675,205 .30 2.8 85,358 .30 2.650,537 .18 2.5 57,321 .19 The average percentage of the metered supply used for Trade Purposes during ten years prior to 1894 is 91.65, and for Public Uses during six years is 2.55, slowly decreasing. Applying these percentages to the total metered consumption in 1899, we obtain the following approximate result: 1899 | 50,664,835 || 46,434,321 | 23.85 || 1,266,620 | .65 The balance being considered as metered Domestic Consumption. |