Factors are such numbers as multiplied together will produce a required number. A Prime Number is one that cannot be resolved into two or more factors; or, it is a number exactly divisible only by itself and unity. A Composite Number is one that can be resolved into factors. Average Height and Weight of Men and Women Source: Life Insurance Medical Directors and the Actuarial Society of America The weights are with shoes on, and usually with coat and vest, which weigh from 3 to 7 pounds Het WOMEN Het: Hgt. Het: Het: | Het: Hat:| Hat: 32°53€|4; 118 122 126 130 134 121 124 128 132 136 20-24 119 127 131 135 139 142 Wgt. Wgt. Wgt. Wgt. Wgt. Wgt. Wgt. Wgt. Wgt. Wgt. Wgt. Wet 25-29 124 126 129 132 30-34 127 35-39 129 131 40-44 129 132 136 140 136 139 143 5'8" 5' 9" 5' 10" 5' 11" 6' 6'1" 6' 2" 6' 3" 5' 6" 5' 7" 5' 8" 5' 9" 5' 10" 5'11" 139 6' 143 147 151 15-19 140 20-24 146 150 154 145 150 155 157 167 The figures in the above tables (except the top 15-19 line in each "Medico-Actuarial Mortality Investigation" published in 1912. table) are taken from the A similar investigation was made in 1929 jointly by the Actuarial Society of America and the Association of Life Insurance Medical Directors and reported in the "Medical Impairment Study" (1929). The data from this study agreed so closely with those of the previous one that changes in the table were recommended for only those ages below 20. Accordingly, the figures in both tables (except those in the top 15-19 lines in each table) represent the results of the 1912 and 1929 ir.quiries. THE ORGANS OF THE HUMAN BODY Source: Arthur MacDonald, Anthropologist, Washington, D. C. International Atomic Weights, 1941 (The Chemical Elements) Source: The Journal of the American Chemical Society Atomic weight is the estimated weight of an atom of an element compared with an atom of oxygen as 16. The table of the chemical elements was founded in 1871 by the Russian chemist, Mendelyeev. He arranged them according to their properties. Later they were numbered according to their weight. Density (Actual Weight) of Chemical Elements Source: Smithsonian Institution Physical Tables (Grams per cubic centimeter. To reduce to pounds per cubic foot, multiply by 62.4) Water has not changed in its chemical composition (H2O) in the last 2,000,000 years. This has been learned by analyzing oxygen liberated from ancient rocks. WEIGHT OF SOLIDS OTHER THAN WOOD (Lbs. Per Cubic Foot) 125-175 Corundum. 245-250 Ivory... 157 Lime: Mortar. Basalt.. 150-190 Dolomite. Bone. 106-125 Emery Brick. 87-137 Feldspar 187 Porcelain. 57.2 Porphyry. 114-120 Pyrite.. 103-111 Quartz. 167-171 Rock salt. 306-324 Sandstone. 231-256 Serpentine. 143-156 162-181 309-318 165 136 134-147 156-166 Butter 53-54 Flint. 160-177 Slate. 162-205 The weights of wood when green, as here recorded, include the moisture present at the time the trees were felled, and are based on the average of heartwood and sapwood pieces as represented by test specimens taken from pith to the bark. The air-dry weights are for wood at a moisture content of 12 percent, which is approximately the condition reached without artificial heating by material sheltered from precipitation in the North Central States. The weights per 1,000 board feet are based on nominal or full size. Since nominal and actual size of softwood lumber often vary considerably, this difference must be taken into consideration in estimating the actual weight of softwood lumber per 1,000 board feet. For example, a nominal 1-by-8-inch softwood board actually measures about 25/32 by 71⁄2 inches, and the ratio between actual and nominal cross section is: 25/32 X 72 = 0.732 1 X 8 Then the actual weight of 1,000 board feet of, for example, Sitka spruce 1- by 8-inch boards at 12percent moisture is approximbately 2,330 × 0.732= 1,710 pounds. The decorative value of wood depends upon its color, figure, luster, and the way in which it takes fillers, stains, fumes, and transparent finishes. The Tamarack. 35 2,920 Walnut, black. 52 34 2,830 47 37 3,080 58 38 3,170 sapwood of all species is light in color and in some species it is practically white. The white sapwood of certain species, such as maple, makes it preferable to the heartwood for specific uses. In some species, such as hemlock, the true firs, basswood, cottonwood, and beech, there is little or no difference in color between sapwood and heartwood, but in most species the heartwood is darker and fairly uniform in color. Wood kept either constantly dry or continuously submerged in water does not decay, regardless of species or of the presence of sapwood. A large proportion of the wood is kept so dry at all times that it lasts indefinitely. Moisture and temperature. which vary greatly with local conditions, are the principal factors affecting the rate of decay. When exposed to conditions that favor decay, wood in warm, humid areas of the United States deteriorates more rapidly than that in cool or dry areas. High altitudes, as a rule, are less favorable to decay than are low altitudes because the average temperatures are lower and the growing seasons for fungi, which cause decay, are shorter. The natural decay resistance of all common native species of wood lies in the heartwood. When untreated, the sapwood of substantially all species has low resistance to decay and usually has a short life under decay-producing conditions. |