UNITS

LenetH. The unit is the Metre, already described. WEIGHT. The unit is the Gram, which represents a cube of pure water at greatest density, the edge being one hundredth of a metre. 1,000 grams make a Kilogram. For commercial purposes, the gram is more clearly defined as 1/1000 part of a Standard Kilogram—a block of platinum-iridium—as preserved in the archives of the International Metric Commi ion. Capacity. The unit is the Litre, which represents the space occupied by 1 kilogram of pure water at the greatest density, forming a cube of which the edge is 1/10 of a metre. SURFACE. The unit is the Are, which equals 100 square metres. The principal denominations in every-day use in the countries where the metric system is univer sally employed are: [s. 755]