The progressive legislation in connec tion with mines has proved beneficial in diminishing the proportion borne by the accidents to the number of miners em ployed. Great improvements have re cently been made in sinking shafts, safety lamps, underground haulage, coal-cutting machinery, worked by coin pressed air and electricity, and pump. ing apparatus. Better methods of sort ing, picking, and washing coal have been adopted. Good progress has also been made in the application of steel girders as props and bars, and in reduc ing the cost of coal consumed at col lieries. By means of forced draught and better mechanical stoking much coal practically unsalable has been utilized to great advantage. But by far the most appreciable good that has been done in connection with mining in recent years has been the scientific investigations carried on by the BUREAU OF MINES (q. v.) respecting the causation and preven tion of explosions in coal mines, and im proved means recommended and adopted to diminish, if not minimize, these dis asters, where many lives have been lost and much valuable property has been destroyed.
In England and Ireland the crown has the right to all mines of gold and silver; but where these metals are found in mines of tin, copper, iron or other baser metal, then the crown has only the right to take the ore at a price fixed by statute. In Scotland gold mines belong to the crown without limitation, and sil ver mines when three-halfpence of silver can be extracted from the pound of lead. As a general rule, in the United States as well as in Great Britain, whoever is the owner of freehold land has a right to all the mines underneath the surface, for his absolute ownership extends to the center of the earth; but under special grants and contracts it is not uncom mon for one person to be owner of the surface of the land and another to be owner of the mines beneath; or several persons may be owners of different kinds of mines lying one above the other in dif ferent strata. On the public lands of the United States, a title or license may be obtained by any citizen from the gen eral land office at Washington, at the rate of $5 per acre of surface pre-empted.