THE METRIC SYSTEM.

DEFINITIONS.

108. The Metric System is so called because the meter is the unit upon which the system is based.

NOTE. The French originated this system of weights and measures at the close of the last century, and its use in France became obligatory in 1841. The Metric System is now legal in nearly all civilized countries, and, in several, it is making its way rapidly into general use. In 1866, its use was legalized, in the United States, by act of Congress. It is in general use by scientific men throughout the world.

All the units of the other measures are derived in a simple manner from the meter. Thus,

The Meter is the unit of Length.

It is very nearly one ten-millionth (.0000001) part of the quadrant extending through Paris from the equator to the pole.

The Ar is the unit of Land Measure.

It is a square whose side is 10 meters.

The Liter is the unit of capacity.

It is a vessel whose contents are equivalent to a cube the edge of which is .1 meter.

The Gram is the unit of Weight.

It is the weight of a cube of pure water whose edge is .01 meter.

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The name of each denomination indicates at once its relation to the unit of the measure. Thus,

1. The names of the lower denominations are formed by prefixing to the name of the unit the Latin numerals milli (.001), centi (.01), and deci (.1).

For example, a millimeter is one thousandth of a meter; a centigram is one hundredth of a gram; and a deciliter is one tenth of a liter.

2. The names of the higher denominations are formed by prefixing to the unit the Greek numerals deka (10), hekto (100), kilo (1000), and myria (10000).

For example, a dekameter is ten meters; a hektoliter is one hundred liters; a kilogram is one thousand grams; and a myriameter is ten thousand meters.

Since in the Metric System 10, 100, 1000, etc., units of a lower denomination make a unit of a higher denomination, it follows that,

1. A number is reduced to a LOWER denomination by removing the decimal points as many places to the RIGHT as there are ciphers in the multiplier.

2. A number is reduced to a HIGHER denomination by removing the decimal point as many places to the LEFT as there are ciphers in the divisor.

MEASURES OF LENGTH.

109. The Meter is the unit of length; it is legal in the United States at 39.37 inches.

NOTES.-1. Its length is also a little less than 1.1 yards, or nearly 3 ft. 3 in., which may be remembered as the rule of the three threes. Elem. 12.

2. The decimeter and its divisions are shown in an engraving on

the preceding page.

3. Standard meters have been provided by the United States, and copies have been furnished to the several states.

TABLE.

10 millimeters, marked mm., are 1 centimeter, marked cm.

NOTE. The measures chiefly used are the meter and kilometer. The meter, like the yard, is used in measuring cloth and short distances; the kilometer is used in measuring long distances.

1. Reduce 3.825 m. to centimeters.

SOLUTION. To reduce meters to centimeters, multiply by 100. Write 3825, and place the decimal point between 2 and 5, two orders farther to the right than it is in 3.825 Ans. 382.5 cm.

2. Reduce 1025.5 m. to kilometers.

SOLUTION. To reduce meters to kilometers, divide by 1000. Write 10255, and place the decimal point between 1 and 0, three orders farther to the left than it is in 1025.5 Ans. 1.0255 Km.

3. Reduce 2.15 Dm. to centimeters.

SOLUTION.-To reduce dekameters to centimeters, multiply by 10 X 100 1000. Write 215 and annex a cipher.

4. Reduce 2.3 dm. to hektometers.

Ans. 2150 cm.

SOLUTION. To reduce decimeters to hektometers, divide by 10 X 100 1000. Write 23, prefix two ciphers, and place the decimal point before them.

=

Ans. .0023 Hm.

110. The Ar is the unit of Land Measure; it is legal at 119.6 square yards

TABLE.

100 centars, marked ca., are 1 ar, marked a.

100 ars

"1 hektar, 66 Ha.

NOTES.—1. An ar is 100 square meters, marked m2. The hektar is very nearly 2 acres.

2. For measuring other surfaces, squares of the meter and its subdivisions are used.

1. Reduce 397.8 a. to hektars.

2. Reduce 3.8 a. to square meters.

MEASURES OF CAPACITY.

3.978 Ha.

380 m2.

111. The Liter is the unit of capacity; it is legal at 1.0567 quarts, Liquid Measure.

TABLE.

10 centiliters, marked cl., are 1 deciliter, marked dl.

NOTES.-1. The measures commonly used are the liter and hektoliter. The liter is very nearly a quart; it is used in measuring milk, wine, etc., in moderate quantities. The hektoliter is about 2 bu. 3 pk.; it is used in measuring grain, fruit, roots, etc., in large quantities.

2. Instead of the milliliter and the kiloliter, it is customary to use the cubic centimeter and the cubic meter (marked m3), which are their equivalents.

3. For measuring wood the ster is used; it is a cubic meter.

112. The Gram is the unit of Weight; it is legal at 15.432 grains Troy.

TABLE.

10 milligrams, marked mg., are 1 centigram, marked cg.

10 quintals, or 1000 kilograms, 1 metric ton,

NOTE. The weights commonly used are the gram, kilogram, and metric ton. The gram is used in mixing medicines, in weighing the precious metals, and in all cases where great exactness is required. The kilogram-or, as it is commonly called, the "kilo"-is the usual weight for groceries and coarse articles generally; it is very nearly 2 pounds Avoirdupois. The metric ton is used for weighing hay and other heavy articles; it is about 204 lb. more than our ton.

1. Reduce 1428.06 g. to kilograms.

2. Reduce .28 Kg. to grams.

3. Reduce 1713.5 Kg. to metric tons.

1.42806 Kg. 280 g.

1.7135 M.T.