In West Africa, a unit of length by which cloth was sold, 4 yards (about 3.658 meters). The earliest source for this information is Roberts (see sources, below). That Robert's source had more than a little knowledge of the topic is shown by his use of words like “benda” from Twi, the major language of Ghana. The “tam” of jacktam may be related to the Twi word for cloth, “ntam” (the root is “tam”; Twi adds prefixes as English adds suffixes).¹ The jacktam may have survived to the present day as the piece.

Since 1639 Robert's content has been copied by each succeeding generation of cambists,² almost always without attribution, and suspiciously without corroboration, which shows how dark Darkest Africa has been to metrologists. One repetition is particularly tantalizing.

The entry on the jacktan in the German Wikipedia (dated 7 July 2013) says the jacktan was used in Spanish territories in Africa, for example, Ceuta, Melilla and the associated tiny islands, and also in “Guinea”. If true, this would be very interesting, as from 1415 to 1668, which includes the height of the Portuguese cloth trade, Ceuta was Portuguese, as was São Jorge da Mina, the major European trading post on the Gulf of Guinea, which the Portuguese fortified in 1482. So perhaps the term originated in Portuguese.

However, the only source the Wikipedia entry offers for the Ceuta connection is a badly-constructed page of a Handels-Almanach,⁴ which is headed “Spanische Besitzungen in Africa” (Spanish Dependencies in Africa). It begins with a list of Spanish territories in Africa in the early 19ᵗʰ century; and the rest is largely drawn from Hayes. In all the jacktam references in the literature, only this page in the Handels-Alamach mentions Ceuta, etc. We think it is confused.

1. Christaller, pages 14, 492.

2. For example, in chronological order: Kelly, 1821, page 167; Grund, 1834, page 170; Noback, part 1, 1851 page 313 (attributes to Ricard); Klimpert, 2nd ed 1896, page 163; Guillaume and Volet, 1926. page 8.; and, of course, us.

3. John Vogt.
Notes on the Portuguese Cloth Trade in West Africa, 1480-1540.
The International Journal of African Historical Studies, vol. 8, no. 4, pages 623 - 651 (1975).

4. Handels-Almanach oder Uebersicht des in den verschiedenen Ländern der Erde Wissenswurdigsten für den Handel…
Weimar: Verlag des Landes-Industrie-Comptoirs, 1838.
Page 649.
Digitized by Google.



Their Measure for length in cloth or other commodities, is a Jactam, which is accounted with us 12 foot or two fadome which they cut the one from the other, and in that sort sell their linnen the one to the other and those two fathome by triall of the Dutch make a storke and three quarters, but in woollen they never measure above pieces of one handfull broad, which they so cut off and use for girdles which they weare about their middles, and sell it among themselves in this manner in these pieces abovesaid, and use no other kind of measure save one which they call a Paw, which is ¾I.d. English.

Lewes Roberts, 1638, page 86.


Their measure for Cloth is a Jacktam, reckon'd with us 12 Foot, or 2 Fathom, which they cut the one from the another, and sell their Linen in those small quantities; but in Woollen Goods, they seldom measure to one another Pieces above a Hand's Breadth, which they cut for Girdles.

Hayes, 1739. Page 426.


Guinée (Afrique). Le jachtan vaut 3 aunes, 52 8/10 lignes de Paris (de 524 lignes) [or] 1624 8/10 lignes de Paris [or] 3.6652713 meters.

J. F. G. Palaiseau.
Métrologie Universelle, Ancienne et Moderne, ou Rapport des Poids et Mesures des Empires, Royames, Duchés et Principautés des Quatre Parties du Monde….
Bordeaux: chez Lavigne Jeune, Octobre 1816.
page 151.

Palaiseau's own conversion factor (page 75) is 1 foot = 135.11 lignes de Paris, which agrees with Doursther's later 135.1142. Converting 12 feet with his factor gives 1621.32 lignes de Paris, not 1624.8. Perhaps Palaiseau did have an original source other than Roberts or Hayes. (We have reformatted his table.)

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