Research Note

The following material is an expansion of a message that originally appeared in the SUB-ARCH list. It may prove useful to researchers who need to convert units from the original sources to modern equivalents.

16th Century Iberian Units of Measurement

Spanish Linear Distance:

18th Century French Units of Measurement

Eighteenth century French units are often approximately 10% larger than the equivalent English measures.

Linear Distance:

The span—toise—equaled six feet or 1.95 m.

The nautical league—lieue marine—was one twentieth of a degree or 2,850.4 toises (5,565 meters)

The mile—mille—was one third of a league (950 toises) or 1,855 meters.

The fathom—brasse —was five French feet, or 1.62 meters (as opposed to the English fathom of 6 English feet).

The ell—aune—was 1.188 meters in length (used for measuring sail canvas)

The palm—palme—was 13 lignes or 2.92 cm (used for measuring circumference of masts).

Weight:

One hundred French pounds made the 48.9 kg quintal—quinteau—which is roughly the equivalent of the English hundredweight.

Two thousand French pounds equaled a ton—tonneau—or 978 kilograms. When measuring the burthen of ships, there was also the cubic ton, which is about 42 cubic feet or 1.43 cubic meters.

Liquid Measure:

The French Navy needed to use larger measures, such as the barrique, a cask (roughly equivalent to the English hogshead) which held 242 liters. There is some problem translating French to English terms, as the English in the late 18th century used different measures for wine, ale, beer, and dry goods, none of which correspond exactly to French measures. The closest (about 2.5% smaller) is the English measure used for wine; this therefore is the English equivalent used by Boudriot's translator (Boudriot 1986b: 108). The French Navy also used half-hogsheads or demi-barriques of 121 liters and third-hogsheads or tierçons of 161 liters (equivalent to 1/3 of 2 hogsheads).

The ship's water casks were usually larger than single barriques, and were available in multiples of hogsheads, between two and eight. They were rated as pièces de 2 (482 liters), pièces de 3 (726 liters), pièces de 4 (968 liters), pièces de 5 (1,210 liters), pièces de 6 (1,452 liters), pièces de 7 (1,694 liters), and pièces de 8 (1,936 liters). The larger sizes were used exclusively by slave ships, as the French Navy typically didn't utilize casks larger than pièces de 4.

18th Century British Units of Measurement

Weight:

The hundredweight (cwt.) equaled 112 pounds or four quarters (50.848 kilograms).

The quarter (qr.) equaled 28 pounds (12.712 kilograms).

The pound (lb.) equals .454 kilograms.

The ton is the equivalent of 20 hundredweight or 2,240 lbs. (1,016.96 kilograms)

Other British Measurements:

The ell equals 45 inches or 1.143 meters (4.5 cm shorter than the French ell).

The cord, designating a pile of wood, is usually 8 ft by 4 ft by 4 in. (2.4 m by 1.2 m by 10 cm).

The bushel is 8 gallons or 35.648 liters of dry goods, and the chaldron is 36 bushels (1,283.328 liters).

British Cooperage Measures (18th-19th centuries):

Comparison of English & French measures:

18th Century Swedish Measurements:

Arbitrary Ways to Measure Linear Distance:

References

Boudriot, Jean and Hubert Berti

1993 The History of the French Frigate 1650-1850. Jean Boudriot Publications, Ashley Lodge, Rotherfield, United Kingdom.

Chardon, Roland

1980a The Elusive Spanish League: A Problem of Measurement in Sixteenth-Century New Spain. Hispanic American Historical Review 60: 294-302.
1980b The Linear League in North America. Annals of the Association of American Geographers 70: 129-153

Creswell, John

1972 British Admirals of the Eighteenth Century: Tactics in Battle. Archon, New York.

Hoving, A.J.

1995 Seagoing Ships of The Netherlands. In The Heyday of Sail: The Merchant Sailing Ship 1650-1830, edited by P. Bosscher, pp. 34-54. Conway's History of the Ship, R. Gardiner, general editor. Conway Maritime Press, London.

Hudson, Charles

1997 Knights of Spain, Warriors of the Sun: Hernando de Soto and the South's Ancient Chieftoms. University of Georgia Press, Athens.

Keith, Donald H., Worth Carlin, and John de Bry

1997 A Bronze Cannon from La Belle, 1686: its Construction, Conservation, and Display. International Journal of Nautical Archaeology 26(2): 144-158.

Lavery, Brian

1987 The Arming and Fitting of English Ships of War, 1600-1815. Naval Institute Press, Annapolis, Md.

O'Neill, Timothy P.

2003 Coopering. In Traditional Crafts of Ireland, edited by D. Shaw-Smith, pp. 75-79. Revised edition. Thames & Hudson, New York.

Smith, Roger C.

1993 Vanguard of Empire: Ships of Exploration in the Age of Columbus. Oxford University Press, New York.

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