• Acre: 160 square rods. Originally: the amount of land tilled by one man behind one ox in one day; four by forty rods or four rods by one furlong. Acres were long and narrow to provide more river front access, and because it was difficult to turn the plow around.
• Furlong (furrow length): 40 rods or 1/8 mile or 660 feet. Originally the distance a team of oxen could plow without resting.
• Oxgang: 15 acres or the land tilled by one ox in one plowing season.
• Rod: a measurement of five yards, or sixteen feet and a half. A square rod is equal to 160th of an acre.
