services and a moderate effort be made at finding and stopping the thousands of leaks in street mains and service pipes, this additional supply of 500 million gallons for all boroughs combined, would last thirty years. From this diagram we see further that under the natural growth of the city and with use and waste increasing from year to year at the same rate as heretofore, a supply of about 800 million gallons per day would be exhausted thirty years hence.

We can hope and confidently expect that at some future time public opinion in our large American cities will have become quickened and domestic meters become popular and street waste be strenuously looked after, and that in this way the city of twenty-five or thirty years hence, if it continues to grow at the same rate, can obtain its additional water for use out of a restriction of waste, and can provide filtration out of the saving in expense

for water wasted.

This diagram indicates that if the prohibition against Brooklyn coming east into Suffolk County remains in force and conditions of use and waste in all the boroughs remain about as at present, a supply of 200 million gallons as proposed by the Ramapo Company would be exhausted within ten years, and the 150 million gallons which the Ten Mile can furnish from a large reservoir with dam at Webatuck, would be exhausted in less than eight years.

The Ten Mile River and Upper Housatonic combined would probably meet all demands of waste and use, with the natural growth of the city and with present conditions continued for nearly thirty years, and with the education of the public in methods of waste restriction which we may hope will have by that time been attained, this supply will serve abundantly for a period longer than we can now foresee.

900.

No. 14

DIAGRAM OF PROBABLE RATE OF INCREASE

in Demand for additional Water in
Greater New York - All Boroughs

800.

700.

600.

500.

MILLION GALLONS REQUIRED IN ADDITION TO PRESENT SUPPLY

400.

300.

200.

100.

Best results probably attainable.

Total additional supply required for all Boroughs with

1900.

1905.

1910.

9115

1915.

YEAR

1920.

1940.

MAGNITUDE OF NEW SUPPLY RECOMMENDED.

From a study of the foregoing tables and diagrams I am led to believe that nothing less than a total of 500 million gallons per day should be considered. A supply of 150 to 200 million gallons, if it has to serve for all the boroughs, because of the prohibition against going into Suffolk County, would be exhausted inside of eight or ten years with present conditions continued, or would be exhausted within twelve or fifteen years if a meter was applied to every domestic tap and as much as can be reasonably expected done on replacing leaky service pipes.

I am led to recommend that the investigations take a much broader scope, looking farther into the future than ten or fifteen years, and thus establish a progressive line of development and extension for New York's water supply for a longer future, much as was done for Boston under the direction of the far-sighted Massachusetts State Board of Health, whose plans for ultimate development reach out beyond the Nashua Works now under construction, to the Ware river, the Swift river, and even to the Deerfield, and are so clearly outlined that the development can come step by step and in the end be a harmonious and economical system.

There are all the water sources now on the map that there ever will be and so long as population grows and civilization progresses, the legitimate needs for water must increase, and economy will surely be gained by studying out at the present time the best lines for extension.

THIRD QUESTION.-WATER PRESSURE-FIRE PROTECTION.

The writer, as engineer to an association of large insurance companies, has devoted much time for 14 years past to a study of fire protection, and has had occasion to investigate the progress and the checking of a good many bad fires, and has had occasion to study somewhat broadly the comparative efficiency of the water pressure found in various cities, and has been led to believe that a hydrant pressure of at least 80 pounds per square inch is to be very strongly preferred over a smaller pressure, and that 100 pounds per square inch is probably better, with the modern tendency to higher buildings and with the constantly increasing use of automatic sprinklers in manufacturing and commercial buildings.

It appears feasible to obtain this pressure throughout substantially the whole of New York from a gravity supply; and if the legal authority can be obtained to deliver 800 million gallons per day from the Housatonic, Ten Mile and East Branch sources, with an elevation of 300 feet above the sea at the city limits, this can be delivered at this elevation and pressure at a cost not substantially greater than if delivered at a lower level.

This would do away with all necessity for high service pumping (which now costs the city in Manhattan alone about $70,000 per year for coal and wages, apart from all interest, fixed charges and depreciation); would ultimately save largely in insurance cost (for in the long run rates are always adjusted in proportion to the actual fire loss and to the efficiency of the fire protection); and presents such manifold advantages that I most earnestly recommend that all new work have the utilization of such a pressure in nearly all parts of the city, say, 20 years hence, continually in view, and within 5 years in certain elevated or extra hazardous districts. While I am well convinced that a salt water fire pipe system for the congested commercial district would be an excellent safeguard, and that its cost is remarkably small in proportion to the value of the protection it affords, I venture to suggest that final action on a salt water pipe system be deferred until it is known with certainty what is to be done about securing a gravity supply under a pressure corresponding to an elevation of 300 feet above sea level at the city limits and until the policy with regard to a high pressure distributing reservoir at Park Hill is clearly defined. This need not delay final action on the salt water system longer than until next summer, and meanwhile surveys for it could be in active progress.

As between a salt water fire pipe system like that in Boston and a fresh water high pressure gravity system like that recently constructed in Provi

dence, I believe the fresh water gravity pressure system is much to be preferred, and I am led to believe that with the present complication of pipes and conduits of various kinds now existing in New York's streets all new piping should be in the direction of simplicity, and that while fire pipes may first be run from the high pressure supply it is best in the long run to furnish the high pressure water to every tap, and as safeguard against breakdown to rely on well-designed cut-off valves and cross connections and on a better type of hydrant. The experience of Syracuse in changing from low pressure to high pressure with no serious difficulty or expense is very instructive.

If a high pressure gravity supply is held by those in authority to be inexpedient, then a salt water pipe system for the limited district in the commercial centre where the concentration of value is greatest is well worth its remarkably small cost. It can be so cheaply and quickly put in that perhaps it is worth its cost for the protection it would afford prior to the completion of the high pressure gravity supply. But I would earnestly recommend that if a salt water pipe system is put in, it should be so designed that it can be turned into a fresh water fire pipe system at any future time.

I am not unmindful of the merits and the low cost of a salt water fire pipe system for use in connection with fire boats, and indeed have myself planned salt water fire pipe systems for some of the largest factories along the Atlantic seaboard, but in my judgment and experience a fresh water gravity system such as it is entirely possible to obtain in New York is much to be preferred.

If the Housatonic is secured there will be more than abundant water to supply all the small uses in street flushing, etc., for which salt water might

serve.

The total quantity of fresh water that can be saved by a salt water system is too small a proportion of the entire city supply to cut any material figure in the size of the additional supply of fresh water that is surely needed.