188	THE DIAMOND
	uncertain richness, which may be here or may be there over square miles of very rough country, the odds seem to be largely against adequate returns for an expensive equipment. In the Minas Geraes district, two modern gold dredges adapted to save diamonds have been lately installed on the Jequetinhonha by American companies. The mining laws are another difficulty. Though liberal on the face, there are uncertainties which have proved costly. A former leaseholder may establish a claim, through some irregularity in a previous transfer, after the leasehold has been developed at great expense by a stranger ignorant of prior conditions. It should be remembered that the various States in which diamonds occur make their own laws governing the mining for them, and as they are somewhat complicated, an attempt to state the provisions definitely might prove misleading. As written, they tend to encourage enterprises of that character. Concessions are to be had on apparently easy terms. Persons of any nationality can take out a claim, but the authorities pass on the ability of the applicants to prosecute the work. In a general way, mining lands belong to the State. If diamonds are discovered on private property, the discoverer can be empowered by the State to prospect and mine, by secur­ing the owner against surface damage to the property and paying a tax to the government. If the discovery it made on government lands, he can obtain a concession or a license to dig within certain prescribed limits, and if in the bed of a river, within a certain length of it, by making application to the authorities, and paying a small tax. In the case of a concession he must also prove his financial ability to be adequate to the undertaking. A