Technikatörténeti szemle 10. (1978)

A MÉRÉS ÉS A MÉRTÉKEK AZ EMBER MŰVELŐDÉSÉBEN című konferencián Budapesten, 1976. április 27–30-án elhangzott előadások II. - Zupko, R. E.: Angol súlyok és mértékek

NOTES 1 Readers desiring additional discussions on these and other facets of British metrological history should consult the author's A Dictionary of English Weights and Measures from AngloSaxon Times to the Nineteenth Century (Madison, 1968) and his British Weights and Measures: A History from Antiquity to the Seventeenth Century (Madison, 1977). Both works also contain extensive bibliographies. 2 Roman linear measurement was based upon the Roman standard foot (pes). This unit was divided either into 16 digits or into 12 inches. In both cases its length was the same. Metrologists have come to differing conclusions concerning its exact length but the currently accepted modern equivalents are 296 mm and 11.65 British Imperial (hereafter abbreviated BI) inches respectively. Expressed in terms of these equivalents, the digit (digitus) or 1

/

16 foot was 18.5 mm (0.73 BI inches), the inch (uncia or pollicus) or '/i2 f°

ot was 24.67 mm (0.97 BI inches), and the palm (palmus), always defined as the length of foot, was 74 mm (2.91 BI inches). Larger linear units were the cubit (cubitum) of 1 1

j

2 feet (444 mm or 17.48 BI inches), the pace (passus) of 5 feet (1.48 m or 4.86 BI feet), and the perch (decempeda or pertica) of 10 feet (2.96 m or 9.71 BI feet). 3 The most frequently used itinerary measures were the furlong or stade (stadium), the mile (mille passus), and the league (leuga). The first consisted of 625 feet (185 m or 606.9 BI feet) or 125 paces and was equal to l

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s mile. The second was 5000 feet (1480 m or 4856 BI feet) or 8 stades; for military purposes it was the length of 1000 paces or double steps. The last had 7500 feet (2220 m or 7283 BI feet) or 1500 paces. For very large itinerary or topographical measurements, Roman engineers sometimes employed the schoenus of 4 miles or 20,000 feet (5920 m or 19,424 BI feet). 4 On the latifundia of the Mediterranean world and on the provincial estates the fundamental superficial measure was the actus. Being 120 feet long and 4 feet wide, various combinations of this double furrow length were arranged either horizontally or vertically depending on the type of agricultural operations being performed, the size of the work force, and the peculiarities of local topography. For instance, thirty such acti laid out in a horizontal pattern produced a square actus or actus quadratus, a piece of land 120 feet by 120 feet and equal to approximately 50 BI square perches. This unit was ideally suited for small farming operations. A double actus quadratus made a jugerum, originally a day's work for a yoke of oxen. It was equal to 0.623 BI acre or 28,800 BI square feet. If this most commonly used land parcel were doubled in size a bina jugera or heredium was produced. It was approximately 25 per cent larger than the BI acre. The managers of large estates preferred to subdivide their fields into blocks consisting of 4 heredia arranged in a vertical line. This rendered a strip of land 480 feet long and 120 feet wide. 6 The principal Roman capacity measures were the hemina, sextarius, modius, and amphora for dry products and the quartarus, sextarius, congius, urna, and amphora for liquids. As with linear measures and weights, there is no general consensus or agreement among metrologists as to their metric or BI equivalents. Since Roman writers did not define capacity measures in terms of cubic inches but rather as fractions or multiples of the sextarius, it is necessary to rely completely on the calibration of any given number of extant standards. Since to two standards are ever identical, only an approximate cubic capacity can be determined. In the case of the sextarius, the mean generally agreed upon today is 35.4 BI cubic inches or nearly 1 BI pint (0.58 1). The hemina or half-sextarius, based on this mean, was 17.7 BI cubic inches (0.29 1). Sixteen of these sextarii made the modius of 566.4 BI cubic inches (9.28 1) and 48 of them made the amphora of 1699.2 BI cubic inches (27.841). In the liquid series, the quartarus, or 1

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4 sextarius of 35.4 BI cubic inches, was 8.85 BI cubic inches (0.145 1). Six of these sextarii made the congius of 212.4 BI cubic inches (3.48 1), 24 sextarii made the urna of 849.6 BI cubic inches (13.92 1), and, as in dry products, 48 sextarii were equal to one amphora. 6 Prior to the third century B.C. the standard for all Roman weights was the as or Old Etruscan or Oscan pound of 4210 BI grains (272.81 g). It was divided into 12 ounces of 351 BI grains (22.73 g) each. However, in 268 B.C. a new standard was created when a silver denarius was struck to a weight of 70.5 BI grains (4.57 g). Six of these denarii or "pennyweights" were reckoned to the ounce (uncia) of 423 BI grains (27.41 g) and 72 of them made the new pound (libra) of 12 ounces or 5076 BI grains (328.9 g). This pound was brought to Britain and became the standard here, as well as in the rest of the Empire, for weighing gold and silver and for use in all commercial transactions. For mercantile purposes, this new pound had three subdivisions.