sack

Contents

1. A unit of mass for wool in England.

2. A unit of mass in Scotland.

3. A standard measure, based on mass, used for cotton in England.

4. A standard capacity measure for coal in England.

5. A unit of capacity in the Netherlands.

1

In England, before 13th – 19th centuries, an important unit of mass used for wool, = 350 pounds before approx. 1256 and 364 pounds thereafter.

The original magnitude of the sack may have been influenced by the monetary value of the wool. A law of the tenth century (III Edgar 8.2) states “And a wey of wool shall be sold for 120d. And no one shall sell it at a cheaper rate.”¹ A wey of wool is half a sack, so a sack would have been sold for 240 pence, or exactly a pound.

Thirteenth-century documents define the sack as 28 stone each of 12½ pounds avoirdupois, or 350 pounds, but its value was already shifting.

Wholesale quantities of wool were weighed on the King's balance, and it was the custom to add extra wool until the balance tipped in the buyer's favor. Such a procedure is easily abused by a weighmaster who wishes to favor the buyer, since the scales can be as easily tipped by an extra ten pounds as an extra two. So London abolished this practice effective December 6, 1256. To compensate buyers for the change to exact weight, they were given a well-defined extra bit, called “tret” or “cloffe”, which was set at an extra four pounds for every hundred pounds purchased.² A 350-pound purchase (the old sack) thus became 350 plus 14 (14 = 4 pounds × ³⁵⁰/₁₀₀), or 364 pounds. That weight was coincidentally almost the same as 500 libbrae of the city of Florence, one of England's most important customers in the wool trade.

The 364-pound sack was legalized by Edward III in 1340,³ when he declared the sack weighed 26 stones, each stone weighing 14 pounds. These values for the stone and sack survived for six centuries. But see stone.

In Tudor times, for customs purposes 240 woolfells were considered equal to 1 sack.

For a full discussion of this subject, see:

1. Agnes Jane Robertson.
The Laws of the Kings of England from Edmund to Henry I.
Cambridge: Cambridge University Press, 1925.

Page 29.

2. R. D. Connor.
The Weights and Measures of England.
London: Her Majesty’s Stationery Office, 1987.

3. Statute 14 Edward III Stat i c 21 (1340).

2

In Scotland, a unit of mass used for wool, 24 stone of 16 pound each.

3

In England, a unit of mass used for cotton, = 150 to 400 pounds.

4

In England, a unit of capacity used for coal, described in 1552 as equaling 4 bushels. An act of Parliament in 1730 defined the capacity of the sack as 3 bushels (the bushel had shrunk since 1552), and fixed the dimensions of the physical object: 50 inches long and at least 20 inches broad. Twenty-eight years later Parliament lengthened the sack by 2 inches. In the Act of 1824 that established imperial measure, the sack was set at 3 heaped imperial bushels, about 136.3 liters.

The Act of the 3rd of George the 2nd, A. D. 1730, Chap. 26, Sect. 11, enacts (for preserving and discovering Frauds and Abuses in the measuring of Coals) that all Coals, landed at any Wharf, or other landing place on the River Thames, and which shall be carried to any Places within the Cities or Suburbs of London and Westminster, shall be carried in linen Sacks, sealed and marked, which Sacks shall be full four Feet and two Inches in Length, and twenty-six inches in Breadth after they shall be made; and all Dealers in Coals shall use no other; and Makers of Coal Sacks shall make them of the Dimensions aforesaid at least.

Great Britain. Parliament. House of Commons.
Reports from committees of the House of Commons which have been printed by order of the House, and are not inserted in the Journals. Volume II.

[Lord Carysfort's Commission.]
Report from the committee appointed to inquire into the original standards of the weights and measures in this kingdom, and to consider the laws relating thereto. 26 May 1758
London.

Page 418.

5

In the Netherlands, a unit of capacity: Amsterdam, 79.530 liters; in Vlissingen, 86.349 liters.