Whenever it shall appear from the land office records in the Department of Internal Affairs that warrants for land belonging to the Commonwealth have been legally granted, or that town lots have been sold by a commission representing the Commonwealth in conformity with the law authorizing the sale of such lots, and when there is no lien entered on record against such land or lots in the unpatented land lien docket authorized by the act of May twentieth, one thousand eight hundred and sixty-four,¹ and its supplements,² in the respective county in which said lands may lie, it shall be the duty of the Secretary of Internal Affairs to grant patents for such lands or lots in the usual form and manner, upon proof of ownership of such land or lots, and the payment of the patent fees now authorized by law.