Metric and Imperial Systems of Weights and Measures

Appendix.

The initial unit of the metric system is the Metre (m.) or unit of length, representing one-fourth-millionth part of the circumference of the earth round the poles.

The unit of mass is the Gramme (g.), and represents the weight of one cubic centimetre of water at its maximum density (viz. 4° C. and 760 mm. mercury pressure).

The unit of the measure of capacity is the Litre (l.), and represents the volume of a kilogramme of distilled water at its maximum density.

The decimal subdivisions of each of the units are designated by the Latin prefixes milli = 1/1000; centi = 1/100; deci = 1/10; the multiples of each unit by the Greek prefixes deka = 10; hecto = 100; kilo = 1000; myria = 10,000.

For a comparison of the values of some of the more frequently employed expressions of the Metric System and the Imperial System, the following may be found convenient for reference:

Length:

1 millimetre (= 1 mm.) = 1/25 of an inch.

1 centimetre (= 1 cm.) = 2/5 of an inch.

1 inch (1") = 25 millimetres or 2-1/2 centimetres.

Mass:

1 milligramme (= 1 mg.) = 0.01543 grain (or approximately 1/64 grain).

1 gramme (= 1 g.) = 15.4323 grains.

1 "kilo" or kilogramme (= 1 kgm.) = 2 pounds, 3-1/4 ounces avoirdupois.

1 pound avoirdupois (= 1 lb.) = 453.592 grammes.

1 ounce avoirdupois (= 1 oz.) = 28.35 grammes.

1 grain = 0.0648 gramme or 64.8 milligrammes.

Capacity:

1 cubic centimetre (= 1 c.c.) = 16.9 minims imperial measure.

1 litre (= 1 l.) = 35.196 fluid ounces imperial measure.

1 fluid ounce imperial measure (= 1 ℥) = 28.42 cubic centimetres.

1 pint imperial measure (= 1 O.) = 568.34 cubic centimetres.

1 gallon imperial measure (= 1 C.) = 4.546 litres, or 10 pounds avoirdupois, of pure water at 62° F. and under an atmospheric pressure of 30 inches of mercury.

Factors for Converting from one System to the Other.

To convert grammes into grains × 15.432.

To convert grammes into ounces avoirdupois × 0.03527.

To convert kilogrammes into pounds × 2.2046.

To convert cubic centimetres into fluid ounces imperial × 0.0352.

To convert litres into fluid ounces imperial × 35.2.

To convert metres into inches × 39.37.

To convert grains into grammes × 0.0648.

To convert avoirdupois ounces into grammes × 28.35.

To convert troy ounces into grammes × 31.104.

To convert fluid ounces into cubic centimetres × 28.42.

To convert pints into litres × 0.568.

To convert inches into metres × 0.0254.