Labor does not necessarily become less as times go on“It may even happen, at the worst, that the utilization of a natural source of energy involvesmore labour than the human expenditure of energy one is seeking to replace. In this field it is chance which decides; for the discovery of a new and easily accessible source of energy or of an economic transformation process for a known source of energy is not one of those things one is sure of reaching on a basis of thinking methodically and spending the necessary time thereon.