PERCH, in land-measuring, a rod or pole of sixteen feet and a half in length. Of these rods, forty in length and four in breadth make an acre of ground. But, by the customs of several counties, there is a difference in this measure. In Staffordshire the perch is twenty-four feet; in the forest of Sherwood it is twenty-five feet, the foot being there eighteen inches long; and in Herefordshire the perch of ditching is twenty-one feet, the perch of walling sixteen and a half feet, and a pole of denshied ground is twelve feet.