2. Evolution of Geometric Land-measures
While smaller units, such as the superficial rod, can easily be conceived as square, the larger arable units have, or have had, a peculiar form which still attaches to them. The peasant, whose mind’s eye can perceive the square rod or toise or verge, refers the rood or the acre, the vergée or the arpent, to the familiar length of the furrow and to the breadth of the rod or of the four-rod acre-breadth equal to a cricket-pitch. These lengths and breadths will long be his essentially concrete standards of field-measurement.
While some legal units of surface have recognised the customary furrow-length as an element of this form, others have always been undefined as to form.
In ancient Egypt the land was surveyed by the state, not only for revenue purposes, but because of the Nile overflow effacing the land-marks usual in other countries.
‘Hence land-measuring appears to me to have had its beginning, and to have passed over to Greece’ (Herodotus). The agrarian unit of Egypt, called by the Greeks aroura, a plough-land, was a square, each side being a Khet or cord, of 100 royal cubits = 172 feet or 57-1/3 yards. The square khet is represented by the present Egyptian feddan al risach of 20 lesser qasáb (each 20 × 4 Hashími cubits) = 170·4 feet square = 2/3 acre.
Ten square khet made the usual land-holding. This unit, = 6·79 acres, corresponds closely to 10 modern feddan, to the véli or oxgang unit of Southern India, and to the 7 acres of arable in the medieval English boor’s yard-land. That the ancient Egyptian oxgang was 10 khets in a line, giving if required a furrow of 573 yards easy in muddy alluvial soil, seems certain, for its hieroglyphic is a line of ten small squares. This is exactly the primitive form of the English acre, 10 × 1 chains.
In ancient Greece the unit of land-measure was the plethron of 10 rods (kalamoi) each of 10 Olympic feet, = 101·33 English feet. Had it a concrete agrarian form? Evidently the square plethron (= 0·235 acre or nearly a rood) was much too short for a plough-unit; but the larger unit was the tetragyon, i.e. a four-rood field, and with the four square plethra end-on-end, this Greek acre afforded a furrow-length of 135 yards. So it is probable that the tetragyon, 135 × 33-3/4 yards, = 0·94 acre, was the usual concrete agrarian unit.
A common size of land-holding was 12 × 12 = 144 plethra, = about 34 acres, a size corresponding to our medieval oxgang.
In ancient Italy land was measured by the Roman decempeda or pertica, the 10-foot perch or rod, = 9·725 feet.
A strip of land 120 × 4 Roman feet made an Actus, probably the breadth of a double furrow, up and down. The square actus, actus quadratus, = 30 acti = 120 × 120 feet, about 50 square rods.
Two square acti made a Jugerum, the day’s work for a yoke of oxen, = 0·623 acre.
Four square acti, bina jugera, made the Heredium, = 1·246 acre.
How were the four square acti arranged? Were they in a square 240 × 240 feet? No doubt that would be the official form of the heredium; but it is probable that, as I have assumed for the Greek tetragyon of 4 square plethra, the 4 Roman acti would be, when convenient, practically arranged in a line, thus giving an agrarian unit of 480 × 120 feet and a furrow of about 160 yards, which is nearly one-tenth of the 5000 feet Roman mile.[[15]]
The official division of the field was based on the jugerum; this being divided, on the duodecimal or uncial system, into 12 unciæ, each of 24 square perticæ, the latter being the scruples, the qiráts, of the Roman land-ounce. Here we see the uncial system overshadowing the decempeda; for if the jugerum could be divided into 12 ounces of 240 × 10 feet and these into 24 scruples of 10 feet square, each of its two acti might also be divided into 100 sections of 12 feet square, or the double jugerum into 100 sections of 24 feet square. It is probable that this would be a more popular division than that based on the decempeda; for it is certain that a rod of 16 spans = 12 feet was used; it was the Græco-Roman akena (from akis, goad), a gad or rod.
The Heredium passed to Gaul, where it established itself in the north, becoming the French arpent, 100 square perches, each of 6 aunes (= 24 Roman feet) square, so that the arpent is identical with the heredium, and was divided on the plan I have suggested as that of the Roman land-measure. But the arpent rarely coincided with the standard of the Paris government, and both seed-measures and work-measures, of fixed area, were often preferred. Where the coutumes de Normandie are still in almost full force and are cherished by the people, the principal unit of land-measure was, and is still, the Acre de Normandie, containing 160 perches of 24 feet square. The standard of the foot varies; sometimes it is the royal foot, sometimes the Roman foot, retained by the device of taking 11 royal inches for a foot. The ancient standard of this acre is thus expressed in law-Latin: Pertica terræ fecit 24 passus seu soleas pedis; 40 perticæ faciunt virgatam; duæ virgatæ faciunt arpentum; 4 virgatæ faciunt acram. ‘Passus’ is here a foot; but sometimes it meant a pace, half of the Roman pace which is here represented by the brasse of 5 royal feet = 1·624 metre. So in Normandy land-measure the pas = 32 inches and the Caux peasant reckons his vergée as 100 × 20 paces = 88·8 × 17·76 yards. These concrete forms of land-unit are dying out, yet everywhere traces of it can be found in conversation with old peasants.
From the South of France to England and Scotland there is a concrete shape recognisable in the large unit of land-measure. The Provençal Saumado of 1600 square cano or toises, the Normandy acre of 160 square rods of 4 toises, the English acre of 160 square rods of 5-1/2 yards, the Scots acre of 160 square rods of 6 ells = 18·53 feet, are all connected by a common tradition of concrete form, and are all made up of four minor units: sesteirado, vergées, roods, &c. Looking back to the land-measures of Greece and Rome we find this same group of four lesser units in the tetragyon and heredium. The law may only recognise abstract superficial standards, but the peasant holds to the concrete units of form convenient for cultivation.