The names of derived metric denominations are formed by prefixing to the name of the primary unit of a measure— Milli (mill'e), a thousandth, Centi (sent'e), a hundredth, Deka (dek'a), ten, Hecto (hek'to), one hundred, Myria (mir'ea), ten thousand. This system, first adopted by France, has been extensively adopted by other countries, and is much used in the sciences and the arts. It was legalized in 1866 by Congress to be used in the United States, and is already employed by the Coast Survey, and, to some extent, by the Mint and the General Post-Office. The meter is used in ordinary measurements; the centimeter or millimeter, in reckoning very small distances; and the kilometer, for roads or great distances. A centimeter is about 3 of an inch; a meter is about 3 feet 3 inches and; a kilometer is about 200 rods, or of a mile. Surface Measures. The square meter is the primary unit of ordinary surfaces. The are (air), a square, each of whose sides is ten meters, is the unit of land measures. TABLE. 100 square millimeters (sq. mm.) = 1 square centimeter (sq. cm.) 100 square centimeters = 1 square decimeter = 15.5 sq. inches. 100 square decimeters = 1 square } = 1550 eq. in., or 1.196 sq. yds. METER (sq. m.) A square meter, or one centiare, is about 103 square feet, or s square yards, and a hectare is about 2 acres. Cubic Measures. The cubic meter, or stere (stair), is the primary unit, of a volume. TABLE. 1000 cubic millimeters (cu. mm.) = 1 cubic centimeter (cu. cm.) = [0.061 cubic inch. 61.022 cubic inches. 35.314 cu. ft. 1000 cubic centimeters = 1 cubic decimeter The stere is the name given to the cubic meter in measuring wood and timber. A tenth of a stere is a decistere, and ten steres are a dekastere. A cubic meter, or stere, is about 13 cubic yards, or about 2} cord feet. Liquid and Dry Measures. The liter (leeter) is the primary unit of measures of capacity, and is a cube, each of whose edges is a tenth of a meter in length. The hectoliter is the unit in measuring large quantities of grain, fruits, roots, and liquids. 10 dekaliters 10 hectoliters = 1 HECTOLITER (hl.) = 2 bushels 3.35 pecks. = 1 kiloliter = 28 bushels 14 pecks. and a A centiliter is about of a fluid ounce; a liter is about 1's liquid quarts, or of a dry quart; a hectoliter is about 23 bushels; kiloliter is one cubic meter, or stere. Weights. The gram is the primary unit of weights, and is the weight in a vacuum of a cubic centimeter of distilled water at the temperature of 39.2 degrees Fahrenheit. 10 grams 10 hectograms 10 myriagrams 10 quintals The gram is used quantities of things. = 1 hectogram = 1 KILOGRAM (k.) = = 1 TONNEAU (t.) avoir. pounds. in weighing gold, jewels, letters, and small The kilogram, or, for brevity, kilo, is used by grocers; and the tonneau (tonno), or metric ton, is used in finding the weight of very heavy articles. A gram is about 15 grains troy; the kilo about 24 pounds avoirdupois; and the metric ton, about 2205 pounds. A kilo is the weight of a liter of water at its greatest density; and the metric ton, of a cubic meter of water. Metric numbers are written with the decimal-point (.) at the right of the figures denoting the unit; thus, 15 meters and 3 centimeters are written, 15.03 m. When metric numbers are expressed by figures, the part of the expression at the left of the decimal-point is read as the number of the unit, and the part at the right, if any, as a number of the lowest denomination indicated, or as a decimal part of the unit; thus, 46.525 m. is read 46 meters and 525 millimeters, or 46 and 525 thousandths meters. In writing and reading metric numbers, according as the scale is 10, 100, or 1000, each denomination should be allowed one, two, or three orders of figures. Egyptian Long Measures. Nahud cubit = 1 foot 5.71 inches. Royal cubit = 1 foot 8.66 inches. Sabbath-day's journey = 3648 ft. Day's journey 7296 feet. = 33.164 miles. = 11.604 Mile (millarium) = 4842 In this last table, where two or more values are given for the same weight, they are from different authorities on the subject. MENSURATION. Definitions. A point is that which has only position. A plane is a surface in which, any two points being taken, the straight line joining them will be wholly in the surface. A curved line is a line of which no portion is straight (Fig. 1). Fig.1 A Curved Line. Parallel lines are such as are wholly in the same plane, and have the same direction (Fig. 2). A broken line is a line composed of a series of dashes; thus, An angle is the opening between two Fig.2 lines meeting at a point, and is termed a right angle when the two lines are perpendicular to each other, A A A A are acute angles, Fig.3 RR RR Polygons. A polygon is a portion of a plane bounded by straight lines. A triangle is a polygon of three sides. A scalene triangle has none of its sides equal; an isosceles triangle has two of its sides equal; an equi lateral triangle has all three of its sides equal. A right-angle triangle is one which has a right angle. The side opposite the right angle is called the hypothenuse; the side on Fig. 4. which the triangle is supposed to stand is called its base, and the other side, its altitude. Fig. 5. Fig. 6. Fig. 7. Isosceles Triangle. Equilateral Triangle |