Symbol. At. Wt. Sp. Gr. Aluminum Al 27.5 2.56 Antimony Sb 122.0 6.70 Arsenic As 75 5.70 Barium Ba 137 4.00 Bismuth Bi 210 9.7 Calcium Ca 40 1.58 Carbon C 12 3.50 Chromium Cr 52.5 6.81 Cobalt Co 58.8 7.70 Copper Cu 63.5 8.96 Gold (Aurum) Au 196.77 19.30 Hydrogen H 1.0 0.069 Iodine I 127.0 4.94 Iron (Ferrum) Fe 56.0 7.79 Lead (Plumbum) Pb 207.0 11.44 Manganese Mn 55.0 8.1 Mercury (Hydrargyrum) Hg 200 13.59 Nickel Ni 58.8 8.60 Nitrogen N 14.0 0.972 Oxygen O 16.0 1.105 Phosphorus P 31.0 1.83 Platinum Pt 197.4 21.53 Potassium (Kalium) K 39.0 0.865 Selenium Se 79.5 4.78 Silicon Si 28.0 2.49 Silver (Argentum) Ag 108.0 10.05 Sodium (Natrium) Na 23.0 0.972 Sulphur S 32.0 2.05 Tellurium Te 129.0 6.02 Tin (Stannum) Sn 118.0 7.28 Zinc Zn 65.0 7.14 CHAPTER XII. ODDS AND ENDS. MINER'S INCH. A miner's inch of water varies in different States, and is, therefore, not a fixed quantity. In some States it means the quantity of water that will flow through an orifice one inch square on the bottom or side of a box under a pressure of four inches. Under these conditions a miner's inch will discharge 2259 cubic feet, or 17,648 gallons every twenty-four hours, which is at the rate of 12 gallons a minute. Fifty of these miner's inches are equal to a cubic foot of water discharged every second. One cubic foot of water a second would be sufficient to supply the wants of seven thousand city dwellers. In calculating the amount of water required by a stamp mill it is usual to allow 72 gallons for every stamp, 120 gallons for every pan, 75 gallons for every settler, 120 gallons for every Fruevanner, 30 gallons for a concentrator, 350 gallons for a jig, and 7-1/2 gallons for every horse-power of a boiler each hour. If the water after passing through the mill is impounded and used over again, the loss will be about 25 per cent. LUMBER IN A LOG.