Rent and royalties.—In 1721 one George Sparrow, who had just become the lessee of a coal mine, fraudulently delayed getting a thousand stacks of coal until after the first quarter day, in order to keep off the commencement of his rent. The terms of the lea.se were that he was to pay the first quarter's rent on the quarter day next after he should have dug a thousand stacks. But Sparrow, having dug nearly that amount about a week before the quarter day, employed his workmen in other works, telling some of them that he was not such a fool as to pay a quarter's rent for a few days' work ; "by which means the thousand stacks of coal were not digged till after Lady Day, whereas they might have been digged before" had not Sparrow prevented. Thereupon the lessor brought the action of Green v. Sparrow, and Sparrow was ordered to pay his rent a S from the quarter day prior to which the thousana stacks would have been dug, but for his fraudu lent delay. No rent was payable, in the case of Senhouse v. Harris, for coal used in working the engine of one mine when employed in bringing up the coal from another mine, such engine being at the same time used for keeping the former aline free from water. A licensee mixed coals he had gotten under the licence with those gotten from a colliery which was his own property, and sold them so mixed. He then alleged that the coals gotten under the licence were of less value than the other coals, hut the Court refused to hear this, and held that as they had been mixed by the licensee's own act, he was not entitled to distinguish between the values of the coals. A more or less exhaustion of coal has been frequently pressed upon the Court as a reason for some remission in rent. But a lease of a coal mine is looked upon as a sale of the coal therein, and the rule of CAVEAT EMPTOR (q.v.) is always applied to the case of lessees of such mines. Every one acquainted with property of this character is aware that coal mines are liable to be interrupted by faults. Relief might be granted, however, if all the coal had been gotten by ancient workings. In Ridgway v. Sneyd the Court upheld the right of the lessor to the minimum rent reserved bv the lease, although the coal was proved to be not worth the expense of working; but if the lessor, under the same circumstances, were to sue upon the lessee's covenant to work, he would not be so successful. And if the covenant to pay a minimum rent is an absolute one, that rent will continue to be payable even though the coal is nearly exhausted and the lessee is prevented from continuing to work it except at a ruinous expense. The covenant for rent should therefore have some saving qualification. In one case—Gnyiths v. Rigby—the qualification was that the rent should determine if and when the coal should have been worked out " so far as the same could be fairly wrought." Here it was held that the question whether the coal could be fairly wrought did not depend upon whether it could be worked at a profit or not, or whether any such coal as that leased was worth working; but assuming that coal of the same description could be properly worked, whether, according to the usage of miners, the coal in question could be worked without extraordinary difficulty or expense. What is meant by "fairly" wrought may be a question for a jury to determine. An excess in quantity in one quarter may not, as a rule, be set off against a deficiency in the next.
Duty to work.—In Sharp v. 'Fright, where the only rent reserved was dependent on the quantity raised, and was payable quarterly, it was held that the lessee was bound to commence working immediately, and to proceed continuously. But this obligation must be considered in the light of what has been said above with regard to a lessee's equal right to abandon a lease, the property comprised in which has been totally destroyed or exhausted.
Where the lessees of china-clay were under an obligation to "dig, work, and search" for it as speedily as possible, and in an effective and proper manner with a reasonable number of able-bodied men during the usual working time, the lessors were allowed (Kinsman v. Jackson) to retake possession, under a power to that effect ir. the lease, because the lessees had got no fresh clay for some months, and were only working the old stock. The precise duty to work can only be determined, however, after reference to the actual wording of the covenant in the particular lease. And the mode of working must also be governed by the appropriate covenant. If, for example, a lease only requires that a mine shall be worked and carried on in a proper and work manlike manner, the lessee is not bound to sink a pit if he can carry on the works from an adjoining colliery. Unless there is an express agreement to the contrary, a lessee of a mine can work the minerals by " instroke." When there is an agreement between the landlord and tenant that the latter shall restore the surface as soon as he has worked out the mine, it is the landlord only who has any right to complain if this is not done ; no third party has such a right. If the owner of the mine expects the lessees to support the surface of the mine he should, as a rule, insert in the lease an express provision to that effect. Apart from such a provision the lessee, as against the lessor, is entitled, where he has a lease of all the mineral underneath, to work all the minerals in a proper and workmanlike manner without special regard to the effect of the working upon the surface. His lease is of those minerals, and he has a right to get them in a proper manner. And where a lessee covenants with his lessor to support the surface he is not liable for any subsidence caused by his predecessors. Nor is he liable to the surface owner for a subsidence merely because he happens to be in possession of a partially worked-out mine, and the subsidence has been caused by the under ground workings of his predecessors before the date of his own lease.
Support.—Where the surface of the land belongs to one person and the minerals underneath to another, and there is no qualification of their mutual rights and obligations, the owner of the minerals can only remove them, if he does not thereby cause a loss of support to the surface, or if he adopts means to maintain the surface in its natural state. The right of the surface owner to support does not extend to any buildings he may erect thereon ; it is confined to the surface in its natural state. But it would seem that after twenty years a house acquires a right to the lateral support of the soil around it. If the surface, while unencumbered by buildings and in its natural state, subsides and is injured by the removal of the subjacent mineral strata, although the operation may not have been conducted negli gently, nor contrary to the custom of the country, the surface owner has a right of action against the owner of the minerals for the damage sustained by the subsidence (Hunffries v. Brogden). And this is so though the surface owner is himself the person who grants the minerals to another person. In Earl of Westmoreland v. New Sharlston Collieries Co. the plaintiff was the surface owner, and also the grantor of the minerals to the defendants, and it was there held that the colliery company had no right to let down the surface of the lands, and the Court accordingly restrained them from so doing, even though the result might be to compel them to close their works entirely.