NOTE.—The above figures are introduced to show more vividly the comparison between _bulk and weight_, the size of the different substances, of course, being merely approximate. A study of the Table of Specific Gravities to be found in the next page is worthy of the time and attention. TABLE OF SPECIFIC GRAVITIES. METALS. Iron, (cast) 7·207 „ (wrought) 7·688 Steel (soft) 7·780 „ (tempered) 7·840 Lead (cast) 11·400 „ (sheet) 11·407 Brass (cast) 8·384 „ (wire drawn) 8·544 Copper (sheet) 8·767 „ (cast) 8·607 Gold (cast) 19·238 „ (hammered) 19·361 Gold (22 carats) 17·481 „ (20 „ ) 15·709 Silver (pure, cast) 10·474 „ (hammered) 10·511 Mercury (60°) 13·580 Pewter 7·248 Tin 7·293 Zinc (cast) 7·215 Platinum 21·500 Antimony 6·712 Arsenic 5·763 Bronze (gun metal) 8·700 STONES AND EARTH. Coal (Bituminous) 1·256 „ (Anthracite) { 1·436 { 1·640 Charcoal ·441 Brick 1·900 Clay 1·930 Common Soil 1·984 Emery 4·000 Glass (plalte) 3·248 Ivory 1·822 Grindstone 2·143 Diamond 3·521 Gypsum 2·168 Lime 2·720 Granite 2·625 Marble 2·708 Mica 2·800 Millstone 2·484 Nitre 1·900 Porcelain 2·385 Phosphorus 1·770 Pumice Stone ·915 Salt 2·130 Sand 1·800 Slate 2·672 Sulphur 2·033 WOODS. Ash ·845 Beech ·852 Birch ·720 Oak 1·120 Pine (yellow) ·660 „ (white) ·554 Cherry ·715 Cork ·240 Elm ·671 Poplar ·383 Walnut ·671 Willow ·585 LIQUIDS. Acid Sulphuric 1·851 „ Muriatic 1·200 Spirits of Wine ·917 Alcohol ·790 Oil (turpentine) ·870 „ (olive) ·915 Oil (linseed) ·932 „ (castor) ·961 Pure water 1·000 Vinegar 1·080 Milk 1·032 Sea water 1·029 TO FIND THE WEIGHT OF A CUBIC FOOT OF ANYTHING CONTAINED IN THESE TABLES. _Rule._ Multiply 62·5 lbs. (the weight of a cubic foot of pure water) by the specific gravity of the given body. _Example._ What is the weight of a cubic foot of sea water?