“The bill-states the plaintiffs to have been, since the 10th of April 1821, owners of a grist mill, situated on a branch of the Speedwell river, in Morris county, New Jersey, which, with the pond, the waters flowing into it, and all other appurtenances, they purchased on that day, at a sale thereof made by the administrator of Ural Tuttle, under an order of the orphan’s court, and received a regular conveyance therefor.