Note 30 — Chapter II
Reading edition
In order to secure the increased output the number of miners was increased much more than in proportion, namely from 59,000 in 1913 to 171,000 in the first half of 1921. As a result, the cost of production of lignite rose much faster than that of coal. Also since its calorific value is much less than that of coal per unit of weight (even when it is briquetted), it can only compete with coal, unless it is assisted by preferential freight rates, within a limited area in the neighborhood of the mines.