is laid. The end braces are drawn together by an iron tie-rod below the bottom as well as by one above the top of the tank. If a tank more than 5 ft. deep is required, the use of heavy braces may be obviated by tying them together by tie-rods running through the middle of the tank and protected from the action of the water by lead slip tubes wiped to the tank lining. Sizes of house tanks depend on the number of people to be supplied and the probable amount of water each person will use. The amount of water actually required per day has been found by measurement to be about 25 gal. per person. This amount is used approximately as follows: A horse will drink about 7 gal. per day and will need 4 gal. for washing. A cow will drink 5 to 6 gal. per day. A carriage will require 9 to 16 gal. for washing. Tanks supplied from city mains need not be larger than is required to hold a 2 days' supply. Those that are not near a city and that depend on one pump to fill them should hold at least 1 week's supply. Those that depend on rain only should hold at least enough water to last from one rainfall to the other, that is, from 1 to 6 months' supply. WATER DISTRIBUTION IN BUILDINGS. Water Pressure.-When the height, or head, of a column of water is known, the pressure exerted by it at the base of the column may be found by multiplying the head, in feet, by .434; the product will be the pressure, in pounds per square inch. When the pressure, in pounds per square inch, is known, the head may be found by multiplying the pressure by 2.3; the product will be the head of water in feet. Sizes of Fixture Supply Pipes.-The sizes of pipe generally used for supplying water to the various plumbing fixtures are given in the following table: SIZE OF WATER PIPES IN Supply Branches. BUILDING. Capacity of Service Pipes.-The discharge from service pipes and water meters of different sizes, under different conditions, is shown in the table "Capacity of Water-Service Pipes" and its accompanying diagram, Fig. 1. Condition No. 1 represents a discharge at the meter in the cellar; No. 2 represents the discharge at the rear wall of an ordinary cellar; No. 3 represents the discharge about on the first floor, and No. 4 represents the discharge about on the third floor of an ordinary building. Water Measurement.-The quantity of water that passes through service pipes to buildings is measured by means of water meters, a good meter measuring all the water that flows through it, whether it passes as a very small stream or is of the full capacity of the pipe. The accuracy of a water meter may be tested by weighing the water that passes through it. Several tests should be made, drawing the water slowly in some tests, and rapidly in others. When this has been done, by a comparison of the weight of water that actually passed through the meter with the weight of water the meter dial indicated as having passed, the error of the meter can be determined. The table "Approximate Deliveries of Water Meters," gives the size by which meters are designated, which is the diameter of their inlet and outlet pipes, and the maximum delivery of water per minute for which they are rated by the National Meter Co. CAPACITY OF WATER-SERVICE PIPES. (Mr. Kuichling's Table of Discharge, computed for The Thomson Meter Company.) Nominal Diameters of Iron or Lead Service Pipe. Inches. Condition Indicated in Diagram. Pressure in Main. 18 Pounds per Square Inch. Discharge, or Quantity Capable of Being Delivered, in Cubic Feet per Minute, From Pipe Under Conditions Specified in Diagram. No. 1 No. 1 30 1.10 1.92 3.01 6.13 16.58 33.34 7.08 19.14 38.50 52.71 88.16 173.85 444.63 101.80 200.75 513.42 113.82 224.44 574.02 124.68 245.87 628.81 139.39 274.89 703.03 60.87 160.96 317.41 811.79 No. 1.130 2.29 3.99 6.28 12.77 34.51 69.40 183.52 361.91 925.58 .66 1.16 1.84 3.78 10.40 21.30 No. 2 40 12.01 24.59 58.19 118.13 317.23 67.19 136.41 366.30 4.88 .94 1.65 2.60 No. 2 75 No. 2 100 No. 2 130 1.22 2.13 3.36 6.90 18.99 No. 3 30 .55 .96 1.52 No. 3 40 .66 1.15 1.81 3.72 16.45 33.68 92.01 186.78 501.58 106.24 215.68 579.18 121.14 245.91 660.36 47.90 97.17 260.56 57.20 116.01 311.09 No. 3 50 .75 1.31 2.06 .83 1.45 2.29 .94 1.64 2.59 1.10 1.92 3.02 1.26 2.20 3.48 No. 4 30 No. 4 40 .55 8.68 4.24 11.67 23.87 65.18 132.20 354.49 72.28 146.61 393.13 81.79 165.90 444.85 95.55 193.82 519.72 109.82 222.75 597.31 38.63 78.54 211.54 48.68 98.98 266.59 No. 4 50 .65 1.14 1.79 3.69 10.16 20.82 56.98 115.87 312.08 No. 4 60 .73 1.28 2.02 64.22 130.59 351.73 .84 1.47 2.32 73.76 149.99 403.98 1.00 1.74 2.75 5.65 15.58 31.93 87.38 177.67 478.55 101.33 206.04 554.96 |