The sack (abbreviation: sck.) was an
English unit
English units are the units of measurement used in England up to 1826 (when they were replaced by Imperial units), which evolved as a combination of the Anglo-Saxon and Roman systems of units. Various standards have applied to English units at d ...
of
weight
In science and engineering, the weight of an object is the force acting on the object due to gravity.
Some standard textbooks define weight as a vector quantity, the gravitational force acting on the object. Others define weight as a scalar qua ...
or
mass
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different eleme ...
used for
coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.
Coal is formed when ...
and
wool
Wool is the textile fibre obtained from sheep and other mammals, especially goats, rabbits, and camelids. The term may also refer to inorganic materials, such as mineral wool and glass wool, that have properties similar to animal wool. ...
.
It has also been used for other commodities by weight, commodities by volume, and for both weight and volume in the United States.
Wool
The wool sack or woolsack ( la, saccus lanae or ') was standardized as 2
wey of 14
stone
In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its Chemical compound, chemical composition, and the way in which it is formed. Rocks ...
each, with each stone
merchants' pound
The pound or pound-mass is a unit of mass used in British imperial and United States customary systems of measurement. Various definitions have been used; the most common today is the international avoirdupois pound, which is legally define ...
s each (''i.e.'' 350 merchants' pounds or about 153 kilograms), by the time of the
Assize of Weights and Measures
Weights and measures acts are acts of the British Parliament determining the regulation of weights and measures. It also refers to similar royal and parliamentary acts of the Kingdoms of England and Scotland and the medieval Welsh states. T ...
. 12 such sacks formed the wool
last
A last is a mechanical form shaped like a human foot. It is used by shoemakers and cordwainers in the manufacture and repair of shoes. Lasts typically come in pairs and have been made from various materials, including hardwoods, cast iron, an ...
.
[. & & ]
Coal
The coal sack was standardized as an
imperial hundredweight of 112
avoirdupois pounds, approximately 51 kilograms.
Large sack
The large sack was a UK unit of weight for coal. It was introduced by the London, Westminster and Home Counties Coal Trade Act of 1831 (2 Will 4 c lxxvi), which required coal to be sold by weight rather than volume.
The
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against ...
used large sacks holding two hundredweight for
coaling its ships. These sacks were made of
jute bound with
Manila rope
Manila rope is a type of rope made from manila hemp.
Manila hemp is a type of fiber obtained from the leaves of the abacá. It is not actually hemp, but named so because hemp was long a major source of fiber, and other fibers were sometimes ...
. They were filled in the hold of a
collier using a scoop and then a wire cable was run through two iron rings at the mouth of the sack to close and hoist it over to the warship, twelve sacks at a time. A
sack truck :''"Hand truck" may also refer to Pallet jack.''
A hand truck, also known as a hand trolley, dolly, stack truck, trundler, box cart, sack barrow, cart, sack truck, two wheeler, or bag barrow, is an L-shaped box-moving handcart with handles at one ...
would then be used to take each sack to the chute of the warship's coal bunker where they would be emptied. These sacks were large and heavy, weighing at least sixteen pounds when empty, and costing 11 shillings and sixpence before the First World War.
Definition
The large sack was defined as 224 pounds.
Conversion
1 large sack ≡ 2 sacks, equivalent to 2 cwt, 224 lb, or about 102 kg
Other uses
The sack has also been used as a unit of volume. In the
American oil industry
Petroleum has been a major industry in the United States since shortly after the oil discovery in the Oil Creek area of Titusville, Pennsylvania in 1859. The industry includes exploration, production, processing (refining), transportati ...
, a sack represents the amount of portland cement that occupies , and in most cases weighs . Other uses in the US include the measurement by volume of salt, where one sack is , cotton where one sack is and flour, where one sack is just . It has also been used as a measure of volume for dry goods in Britain, with one sack being equivalent to .
In British usage, a sack of flour was equivalent to 20 stone, or one-eighth of a long ton. A sack of coal was 16 stone, or , while the weight of a sack of wool depended on who was selling it. A sack of grower's wool was hundredweight or , whereas a sack of dealer's wool was considerably lighter, at .
References
External links
{{Wiktionary, sackful
Tetbury woolsack race
Units of mass
Customary units of measurement