SECTION II. HYDRAULIC MEMORANDA: WATER-SUPPLY: PUMPS, PIPES, WATER-POWER, &c. Water is composed of oxygen and hydrogen, in the proportion of one part of hydrogen and eight parts of oxygen by weight. Water in freezing expands to the extent of 8 per cent. The specific heat of ice is one-half the specific heat of water. Ice 3 inches thick, will bear the passage of infantry; 5 inches thick. of cavalry and light guns. A cubic foot of fresh snow = 6 lbs. Snow has twelve times the bulk of water. A cubic foot of sea water = 64'10 lbs. Weight of sea water = 1027 the weight of fresh water. 35 cubic feet of sea water = 1 ton. I cubic yard of sea water weighs 15 cwt. I qr. 20 lbs. A column of water 1 inch diameter and 12 inches high = 341 lb. A column of water 1 inch square and 12 inches high = 434 lb. The capacity of a cylinder 1 inch diameter and 12 inches long = '034 gallon. The capacity of a cylinder 12 inches diameter and 12 inches long = 4.895 gallons. = The capacity of a cylinder 1 inch diameter and 1 inch long *00283 gallon. The capacity of a 1-inch cube = '0036 gallon. The capacity of a 12-inch cube = 624 gallons. The capacity of a sphere 1 inch diameter 00188 gallon. 'ine cube of the diameter of a sphere in feet multiplied by 3:26 = gailons. Or the cube of the diameter of a sphere in inches multiplied by 00:88 = gallons. A column of water produces approximately a pressure of half a lb. per square inch, for every foot in height. Pressure of Water.—The side of any vessel containing water sustains a pressure to the area of the side in feet multiplied by half the depth in feet, that product multiplied by 625 will give the pressure in lbs. on each side of the vessel. The pressure in lbs. on the bottom of a vessel is to the area of the bottom in feet multiplied by the depth of water in feet, that product multiplied by 625 will give the pressure in lbs. Contents of Cisterns.—To find the number of gallons contained in a cistern. Multiply the length, width, and depth together, all in feet. This will give the contents in cubic feet, which multiply by 6'24, and the product will be the number of gallons. If the dimensions are in inches use 003607 in place of 6.24. Two dimensions of a cistern being given to find the third, to contain a given number of gallons, multiply the required number of gallons by 16046 if the dimensions are in feet, or by 277 274 if the dimensions are in inches, and divide the result by the product of the two given dimensions. The quotient will be the third dimension required. To find the number of gallons contained in a cylinder, multiply the square of the diameter in feet by the length in feet of the cylinder, and multiply the product by 4'895; or multiply the square of the diameter in inches by the length in feet, and multiply the product by '034; or multiply the square of the diameter in inches by the length in inches, and multiply the product by 00283. The diameter of a cylinder being given, to find the length, multiply the number of gallons by 2043, and divide the product by the square of the diameter in feet, and the quotient is the length in feet. The length of a cylinder being given, to find the diameter, multiply the number of gallons by 2043, and divide the product by length in feet, and the square root of the quotient is the diameter in feet. If the dimensions are in inches, use 353 in place of 2043. WATER AND WATER - SUPPLY. Water is very variable in composition, because it is influenced by the geological formation of the district through which it flows. Water from chalk-springs is generally pure and wholesome, clear and sparkling, of a slight bluish tint, and contains from 6 to 20 grains of mineral matters per gallon. Its temperature is generally about 52° Fahr. It is hard, but softens considerably by boiling. Water from limestone and gypsum strata is hard, softens less by boiling, and is not so wholesome as chalkwater, but it is generally clear and sparkling and of agreeable taste. Water from millstone-grit is pure, and contains from 4 to 9 grains per, gallon of mineral matters. Water from granite is pure, and contains from 2 to 6 grains of mineral matters per gallon. Water from clay-slate is generally pure, and contains from 3 to 5 grains of mineral matters per gallon. Water from gravel and loose sand is generally pure when the gravel and sand are free from impurities, but water from sand rich in salts is impure and unwholesome. Water from impure sand generally contains from 50 to 100 grains of mineral matters per gallon. Water from clay, or from a mixture of clay and sand, is generally impure, and contains from 30 to 130 grains of mineral matters per gallon. Surfacewater from cultivated land, subsoil-water, marsh-water, ditch-water, and water from shallow wells and ponds, are all more or less impure, and dangerous to health. Drinking-water.-An abundant supply of pure water, perfectly protected from impurity in storage, and free from contamination in distribution, is a sanitary necessity in every community. Pure and wholesome water is soft, clear, transparent, slightly sparkling, well aërated, without taste, contains no visible suspended matter, and is either colourless or of a bluish-tint. Unwholesome water has generally considerable permanent hardness and suspended matter, with turbidity; and either a moderately palatable flat taste, or a marked taste, with or without smell, and a yellow or brown |
