CHAPTER V.

WEIGHING AND MEASURING.


~Weighing.~--The system of weights and measures which we have adopted is
the French or metric system; in this the gram (15.43 grains) is the unit
of weight; the only other weight frequently referred to is the
milligram, which is 0.001, or 1/1000 gram. The unit of volume is the
cubic centimetre, which is approximately the volume of 1 gram of water,
and which thus bears to the gram the same relation as grain-measures
bear to grains. It is usual to write and even pronounce cubic centimetre
shortly as c.c., and the only other denomination of volume we shall have
occasion to use is the "litre," which measures 1000 c.c., and is roughly
1-3/4 pints.

The weights used are kept in boxes in a definite order, so that the
weights on the balance can be counted as well by noting those which are
absent from the box as by counting those present on the scale-pan. The
weights run 50, 20, 10, 10, 5, 2, 1, 1 and 1 grams, and are formed of
brass. The fractions of the gram are generally made of platinum or of
aluminium, and are arranged in the following order:--0.5, 0.2, 0.1, 0.1,
and 0.05, 0.02, 0.01, 0.01. These may be marked in this way, or they may
be marked 500, 200, 100, 100, 50, 20, 10, 10; the 500 meaning 500
milligrams.

Some makers send out weights in the series 50, 20, 20, 10, &c.