SURVEYOR’S MEASURE ─────────────────────────────────┬───────────────────────────────────────────── 1 link (7·8 inches) ·22 yards.│1 square link ·048 sq. yds. 10 links 2·2 „ │100 square links 4·84 „ 100 links (1 chain) 22 „ │10,000 sq links (1 sq. chain) 484 „ 10 chains (1 furlong) 220 „ │10 sq. chains (1 acre) 4840 „ ─────────────────────────────────┴─────────────────────────────────────────────
It must be remembered that _the length of the rod determined the length of the mile and the area of the acre_. This is shown in the table on the following page.
BRITISH MILES AND ACRES DERIVED FROM DIFFERENT RODS IN LOCAL USAGE
────────────────────────┬─────────────────────┬───────────────────── LENGTH │ STATUTE │ SCOTTISH ────────────────────────┼─────────────────────┼───────────────────── 1 rod │ 5-1/2 yards │ 6·1766 yards 40 rods = 1 furlong │ 220 „ │ 247 „ 8 furlongs = 1 mile │ 1760 „ │ 1976 „ │ │= 1·123 statute miles │ │ SURFACE │ │ 1 square rod │ 30-1/4 square yards│ 38·15 square yards 40 square rods = 1 rood │ 1210 „ „ │ 1526 „ „ 4 roods = 1 acre │ 4840 „ „ │ 6104 „ „ │ │ = 1·26 statute acre ────────────────────────┼─────────────────────┼───────────────────── LENGTH │ IRISH │ CHESHIRE ────────────────────────┼─────────────────────┼───────────────────── 1 rod │ 7 yards │ 8 yards 40 rods = 1 furlong │ 280 „ │ 8 furlongs = 1 mile │ 2240 „ │ │= 1·278 statute miles│ │ │ SURFACE │ │ 1 square rod │ 49 square yards│ 64 square yards 40 square rods = 1 rood │ 1960 „ „ │ 2560 „ „ 4 roods = 1 acre │ 7840 „ „ │ 10240 „ „ │ = 1·62 statute acre │= 2·116 statute acre ────────────────────────┴─────────────────────┴─────────────────────
_Note._—The Scottish rod or ‘fall’ is six Scottish ells or yards. The Scottish and Irish miles have long been practically obsolete. The Lancashire rod and acre, also the Guernsey perch and acre, are the same as the Irish. The Guernsey land-measures are statute locally; the rood or vergée is the customary unit.[16]
It is worth remark that the 160 square rods of the Irish, Lancashire or Guernsey acre being equal to 1·62 statute acres, 100 of these square rods would make almost exactly a statute acre. A rod of 6·957 yards would give a decimal square rod of 48·4 square yards equal 1-10th square chain, or 1-100th acre, or 1-1000th square furlong. A square-shape acre is 69·57 yards square.