System of measurements
The former Weights and Measures office in
Seven Sisters, London
(590 Seven Sisters Road)
The
imperial system of units
,
imperial system
or
imperial units
(also known as
British Imperial
[1]
or
Exchequer Standards
of 1826) is the
system of units
first defined in the British
Weights and Measures Act 1824
(
5 Geo. 4
. c. 74) and continued to be developed through a series of Weights and Measures Acts and amendments.
The imperial system developed from earlier
English units
as did the
related but differing system
of
customary units of the United States
. The imperial units replaced the
Winchester Standards
, which were in effect from 1588 to 1825.
[2]
The system came into official use across the
British Empire
in 1826.
By the late 20th century, most nations of the former empire had
officially adopted
the
metric system
as their main system of measurement, but imperial units are still used alongside metric units in the United Kingdom and in some other parts of the former empire, notably Canada.
The modern UK legislation defining the imperial system of units is given in the
Weights and Measures Act 1985
(c. 72) (as amended).
[3]
Implementation
[
edit
]
The
Weights and Measures Act 1824
(
5 Geo. 4
. c. 74) was initially scheduled to go into effect on 1 May 1825.
[4]
The
Weights and Measures Act 1825
(
6 Geo. 4
. c. 12) pushed back the date to 1 January 1826.
[5]
The 1824 act allowed the continued use of pre-imperial units provided that they were customary, widely known, and clearly marked with imperial equivalents.
[4]
Apothecaries' units
[
edit
]
Imperial standards of length 1876 in
Trafalgar Square
, London
Apothecaries' units
are not mentioned in the acts of 1824 and 1825. At the time, apothecaries' weights and measures were regulated "in England, Wales, and
Berwick-upon-Tweed
" by the
London College of Physicians
, and in Ireland by the
Dublin College of Physicians
. In Scotland, apothecaries' units were unofficially regulated by the
Edinburgh College of Physicians
. The three colleges published, at infrequent intervals,
pharmacopoeias
, the London and Dublin editions having the force of law.
[6]
[7]
Imperial apothecaries' measures, based on the imperial pint of 20 fluid ounces, were introduced by the publication of the
London Pharmacopoeia
of 1836,
[8]
[9]
the
Edinburgh Pharmacopoeia
of 1839,
[10]
and the
Dublin Pharmacopoeia
of 1850.
[11]
The
Medical Act 1858
(
21 & 22 Vict.
c. 90) transferred to
the Crown
the right to publish the official pharmacopoeia and to regulate apothecaries' weights and measures.
[12]
Units
[
edit
]
Length
[
edit
]
Metric equivalents in this article usually assume the latest official definition. Before this date, the most precise measurement of the imperial Standard Yard was
0.914
398
415
metres.
[13]
Table of length equivalent units
Unit
|
Abbr. or symbols
|
Relative to previous
|
Feet
|
Metres
|
Notes
|
twip
|
|
|
1
⁄
17
280
|
0.000
017
6389
|
typographic measure
|
thou
|
th
|
1.44 twip
|
1
⁄
12
000
|
0.000
0254
|
Abbreviation of "thousandth of an inch". Also known as
mil
.
[14]
|
barleycorn
|
|
333
+
1
⁄
3
th
|
1
⁄
36
|
0.008
4667
|
1
⁄
3
in
|
inch
|
|
3 Bc
|
1
⁄
12
|
0.0254
|
1 metre ?
39.3701 in
|
hand
|
hh
|
4 in
|
1
⁄
3
|
0.1016
|
Still used in some English-speaking (i.e. US and Commonwealth) nations to measure heights of horses.
|
foot
|
|
3 h
|
1
|
0.3048
|
12 in
|
yard
|
yd
|
3 ft
|
3
|
0.9144
|
Defined as exactly
0.9144 m
by the
international yard and pound
agreement of 1959
|
chain
|
ch
|
22 yd
|
66
|
20.1168
|
100 links
,
4 rods
, or
1
⁄
10
of a furlong. The distance between the two
wickets
on a
cricket pitch
.
|
furlong
|
fur
|
10 chains
|
660
|
201.168
|
220 yd
|
mile
|
mi
|
8 furlongs
|
5280
|
1
609
.344
|
1760 yd
or
80 chains
|
league
|
lea
|
3 mi
|
15
840
|
4
828
.032
|
No longer an official unit in any nation.
[
citation needed
]
|
Maritime units
|
fathom
|
ftm
|
2.026
67
yd
|
6.0761
|
1.852
|
The British Admiralty in practice used a fathom of
6 ft
. This was despite its being
1
⁄
1000
of a nautical mile (i.e.
6.08 ft
) until the adoption of the international nautical mile.
[15]
|
cable
|
|
100 fathoms
|
607.61
|
185.2
|
One tenth of a nautical mile. Equal to
100 fathoms
under the strict definition.
|
nautical mile
|
nmi
|
10 cables
|
6
076
.1
|
1852
|
Used for measuring distances at sea (and also in aviation) and approximately equal to one
arc minute
of a
great circle
. Until the adoption of the international definition of
1852 m
in 1970, the British nautical (Admiralty) mile was defined as
6080 ft
.
[16]
|
Gunter's survey units (17th century onwards)
|
link
|
|
7.92 in
|
66
⁄
100
|
0.201
168
|
1
⁄
100
of a chain and
1
⁄
1000
of a furlong
|
rod
|
|
25 links
|
66
⁄
4
|
5.0292
|
The rod is also called
pole
or
perch
and equal to
5
+
1
⁄
2
yards
|
Area
[
edit
]
Table of area units and equivalents
Unit
|
Abbr. or symbol
|
Relative to previous
|
Relation to units of length
|
Square feet
|
Square yards
|
Acres
|
Square metres
|
Hectares
|
perch
*
|
|
|
1 rd
×
1 rd
|
272
+
1
⁄
4
|
30
+
1
⁄
4
|
1
⁄
160
|
25.292
852
64
|
0.002
529
285
264
|
rood
|
|
40 perches
|
1 furlong
×
1 rd
[17]
|
10
890
|
1210
|
1
⁄
4
|
1
011
.714
1056
|
0.101
171
410
56
|
acre
|
|
4 roods
|
1 furlong
×
1 chain
|
43
560
|
4840
|
1
|
4
046
.856
4224
|
0.404
685
642
24
|
square mile
|
sq mi
|
640 acres
|
1 mi
×
1 mi
|
27
878
400
|
3
097
600
|
640
|
2
589
988
.110
336
|
258.998
811
0336
|
Note: *
The
square rod
has been called a
pole
or
perch
or, more properly,
square pole
or
square perch
for centuries.
|
Volume
[
edit
]
Imperial volume units, illustrated as jugs of various sizes
The
Weights and Measures Act 1824
(
5 Geo. 4
. c. 74) invalidated the various different gallons in use in the British Empire, declaring them to be replaced by the
statute
gallon (which became known as the imperial gallon), a unit close in volume to the
ale gallon
. The 1824 act defined as the volume of a gallon to be that of 10 pounds (4.54 kg) of distilled water weighed in air with brass weights with the barometer standing at 30
inches of mercury
(102 kPa) at a temperature of 62
°F
(17 °C).
[18]
The 1824 act went on to give this volume as 277.274 cubic inches (4.54371 litres).
[18]
The
Weights and Measures Act 1963
(c. 31) refined this definition to be the volume of 10 pounds of distilled water of density
0.998
859
g/mL
weighed in air of density
0.001
217
g/mL
against weights of density
8.136 g/mL
, which works out to
4.546
092
L
.
[nb 1]
The
Weights and Measures Act 1985
(c. 72) defined a gallon to be exactly
4.546
09
L
(approximately
277.4194 cu in
).
[19]
Table of equivalences
Unit
|
Imperial
ounces
|
Imperial
pints
|
Millilitres
|
Cubic inches
|
US ounces
|
US pints
|
fluid ounce
(fl oz)
|
1
|
1
⁄
20
|
28.413
0625
|
1.7339
|
0.960
76
|
0.060
047
|
gill
(gi)
|
5
|
1
⁄
4
|
142.065
3125
|
8.6694
|
4.8038
|
0.300
24
|
pint
(pt)
|
20
|
1
|
568.261
25
|
34.677
|
19.215
|
1.2009
|
quart
(qt)
|
40
|
2
|
1
136.5225
|
69.355
|
38.430
|
2.4019
|
gallon
(gal)
|
160
|
8
|
4
546.09
|
277.42
|
153.72
|
9.6076
|
Note:
The millilitre equivalences are exact, but cubic-inch and US measures are correct to 5 significant figures.
|
Unit measures defined by the Weights and Measures Act 1824,
all measures determined by reference to the statute gallon of 277.274 cubic inches.
[18]
Liquid
|
Dry
|
Capacity
|
1
⁄
2
gill
|
|
4.32 cu in (70.8 mL)
|
gill
|
1
⁄
4
pint
|
8.64 cu in (141.6 mL)
|
1
⁄
2
pint
|
1
⁄
2
pint
|
17.38 cu in (284.8 mL)
|
pint
|
pint
|
34.76 cu in (569.6 mL; 0.5696 L)
|
quart
|
quart
|
69.32 cu in (1.1360 L)
|
1
⁄
2
gallon
|
1
⁄
4
peck or
1
⁄
2
gallon
|
138.64 cu in (2.2719 L)
|
gallon
|
1
⁄
2
peck or gallon
|
277.274 cu in (4.54371 L)
|
2 gallons (peck)
|
peck
|
554.548 cu in (9.08741 L)
|
4 gallons (
1
⁄
2
bushel)
|
1
⁄
2
bushel
|
1,109.096 cu in (18.17483 L)
|
8 gallons
|
bushel
|
2,218.192 cu in (36.34965 L)
|
64 gallons
|
quarter
|
17,745.536 cu in (290.79723 L)
|
Note:
The 1824 Act removed the distinction between liquid and dry measure, specifying instead that
the dry quantities shall be unheaped. The metric equivalences shown are approximate.
|
British apothecaries' volume measures
[
edit
]
These measurements were in use from 1826, when the new imperial gallon was defined. For pharmaceutical purposes, they were replaced by the metric system in the United Kingdom on 1 January 1971.
[20]
[21]
In the US, though no longer recommended, the
apothecaries' system
is still used occasionally in medicine, especially in
prescriptions
for older medications.
[22]
[23]
Table of British apothecaries' volume units
[nb 2]
Unit
|
Symbols and
abbreviations
|
Relative to
previous
|
Exact
metric value
[note 1]
|
minim
|
??,
, m, m., min
|
(
1
⁄
9600
pint)
|
59.193
880
208
3
μL
|
fluid scruple
|
fl ?, fl s
|
20 minims (
1
⁄
480
pint)
|
1.183
877
604
1
6
mL
|
fluid drachm
(fluid dram, fluidram)
|
?, fl ?, f?, ? 3, fl dr
|
3 fluid scruples (
1
⁄
160
pint)
|
3.551
632
8125
mL
|
fluid ounce
|
?, fl ?, f?, ? ?, fl oz
|
8 fluid drachms
|
28.413
0625
mL
|
pint
|
O, pt
|
20 fluid ounces
|
568.261
25
mL
|
gallon
|
C, gal
|
8 pints
|
4.54609 L
|
Note:
|
Mass and weight
[
edit
]
In the 19th and 20th centuries, the UK used three different systems for mass and weight.
The distinction between
mass and weight
is not always clearly drawn. Strictly a pound is a unit of mass, but it is commonly referred to as a weight. When a distinction is necessary, the term
pound-force
may refer to a unit of force rather than mass. The troy pound (
373.241
7216
g
) was made the primary unit of mass by the
Weights and Measures Act 1824
(
5 Geo. 4
. c. 74) and its use was abolished in the UK on 1 January 1879,
[30]
with only the troy ounce (
31.103
4768
g
) and its
decimal
subdivisions retained.
[31]
The
Weights and Measures Act 1855
(
18 & 19 Vict.
c. 72) made the avoirdupois pound the primary unit of mass.
[32]
In all the systems, the fundamental unit is the
pound
, and all other units are defined as fractions or multiples of it.
Table of mass units
Unit
|
Pounds
|
In SI units
|
Notes
|
grain
(gr)
|
1
⁄
7000
|
64.798
91
mg
|
Exactly
64.798
91
milligrams.
|
drachm
(dr)
|
1
⁄
256
|
1.771
845
195
3125
g
|
A dram is
1
⁄
16
of an ounce
|
ounce
(oz)
|
1
⁄
16
|
28.349
523
125
g
|
An ounce is
1
⁄
16
of a pound
|
pound
(lb)
|
1
|
0.453
592
37
kg
|
Defined by the
Units of Measurement Regulations 1994
(
SI 1994
/2867)
[33]
|
stone
(st)
|
14
|
6.350
293
18
kg
|
The plural
stone
is often used when providing a weight (e.g. "this sack weighs 8 stone").
[34]
A person's weight is usually quoted in stone and pounds in English-speaking countries that use the avoirdupois system, with the exception of the United States and Canada, where it is usually quoted in pounds.
|
quarter
(qr or qtr)
|
28
|
12.700
586
36
kg
|
One quarter (literally a quarter of a hundredweight) is equal to two stone or 28 pounds. The term
quarter
is also used in retail contexts, where it refers to four ounces, i.e. a quarter of a pound. (The 1824 act defined a quarter as a unit of volume, as above: thus a 'quarter of wheat', 64 gallons, would weigh about 494 lb.
[35]
).
|
hundredweight
(cwt)
|
112
|
50.802
345
44
kg
|
One imperial hundredweight is equal to eight stone. This is the
long hundredweight
, 112 pounds, as opposed to the short hundredweight of 100 pounds used in the United States and Canada.
[36]
|
ton
(t
[
citation needed
]
)
|
2240
|
1
016
.046
9088
kg
|
Twenty hundredweight equals a ton (as in the US and Canadian
[36]
systems). The imperial hundredweight is 12% greater than the US and Canadian one. The imperial ton (or
long ton
) is
2240
pounds, which is much closer to a
tonne
(about
2
204
.6
pounds), compared to the 10.7% smaller North American
short ton
of
2
000
pounds (907.185 kg).
|
Gravitational units
|
slug
(slug)
|
32.174
048
56
|
14.593
902
94
kg
|
The slug, a unit associated with imperial and US customary systems, is a mass that accelerates by 1 ft/s
2
when a force of one
pound
(lbf) is exerted on it.
[37]
|
F
|
=
ma
(
Newton's second law
)
|
|
1 lbf
|
= 1 slug × 1 ft/s
2
(as defined above)
|
|
1 lbf
|
= 1 lb ×
g
/gc (by definition of the pound force
[
citation needed
]
)
|
|
g
|
?
32.174
048
56
ft/s
2
|
|
gc
|
?
32.174
048
56
lbm?ft/lbf?s
2
|
∴
|
1 slug
|
?
32.174
048
56
pounds
|
|
Natural equivalents
[
edit
]
The 1824 Act of Parliament defined the yard and pound by reference to the
prototype
standards, and it also defined the values of certain
physical constants
, to make provision for re-creation of the standards if they were to be damaged. For the yard, the length of a
pendulum
beating
seconds
at the latitude of Greenwich at
Mean Sea Level
in vacuo
was defined as
39.013
93
inches. For the pound, the mass of a cubic inch of distilled water at an
atmospheric pressure
of 30
inches of mercury
and a temperature of 62°
Fahrenheit
was defined as 252.458 grains, with there being 7,000 grains per pound.
[4]
Following the destruction of the original prototypes in the
1834 Houses of Parliament fire
, it proved impossible to recreate the standards from these definitions, and a new
Weights and Measures Act 1855
(
18 & 19 Vict.
c. 72) was passed which permitted the recreation of the prototypes from recognized
secondary standards
.
[32]
Current use
[
edit
]
United Kingdom
Countries using the
metric
(
SI
), imperial and
US customary
systems as of 2019
Since the
Weights and Measures Act 1985
, British law defines base imperial units in terms of their metric equivalent. The metric system is routinely used in business and technology within the United Kingdom, with imperial units remaining in widespread use amongst the public.
[38]
All UK roads use the imperial system except for weight limits, and newer height or width restriction signs give metric alongside imperial.
[39]
A baby bottle that measures in three measurement systems?metric, imperial (UK), and US customary
Traders in the UK may accept requests from customers specified in imperial units, and scales which display in both unit systems are commonplace in the retail trade. Metric price signs may be accompanied by imperial price signs provided that the imperial signs are no larger and no more prominent than the metric ones.
The United Kingdom completed its official partial transition to the metric system in 1995, with imperial units still legally mandated for certain applications such as draught beer and cider,
[40]
and road-signs.
[41]
Therefore, the speedometers on vehicles sold in the UK must be capable of displaying miles per hour. Even though the
troy pound
was outlawed in the UK in the
Weights and Measures Act 1878
, the
troy ounce
may still be used for the weights of precious stones and metals. The original railways (many built in the Victorian era) are a big user of imperial units, with distances officially measured in miles and yards or miles and
chains
, and also feet and inches, and speeds are in miles per hour.
Some British people still use one or more imperial units in everyday life for distance (miles, yards, feet, and inches) and some types of volume measurement (especially milk and beer in pints; rarely for canned or bottled soft drinks, or
petrol
).
[38]
[42]
As of February 2021
[update]
, many British people also still use imperial units in everyday life for body weight (stones and pounds for adults, pounds and ounces for babies).
[43]
Government documents aimed at the public may give body weight and height in imperial units as well as in metric.
[44]
A survey in 2015 found that many people did not know their body weight or height in both systems.
[45]
People under the age of 40 preferred the metric system but people aged 40 and over preferred the imperial system.
[46]
As in other English-speaking countries, including
Australia
,
Canada
and the
United States
, the height of horses is usually measured in
hands
, standardised to 4 inches (102 mm). Fuel consumption for vehicles is commonly stated in miles per gallon (mpg), though official figures always include litres per
100 km
equivalents and fuel is sold in litres. When sold
draught
in licensed premises, beer and cider must be sold in pints, half-pints or third-pints.
[47]
Cow's milk is available in both litre- and pint-based containers in supermarkets and shops. Areas of land associated with farming, forestry and real estate are commonly advertised in acres and square feet but, for contracts and
land registration
purposes, the units are always hectares and square metres.
[48]
Office space and industrial units are usually advertised in square feet. Steel pipe sizes are sold in increments of inches, while copper pipe is sold in increments of millimetres. Road bicycles have their frames measured in centimetres, while off-road bicycles have their frames measured in inches.
Display sizes
for screens on television sets and computer monitors are always
diagonally
measured in inches. Food sold by length or width, e.g. pizzas or sandwiches, is generally sold in inches. Clothing is usually sized in inches, with the metric equivalent often shown as a small supplementary indicator. Gas is usually measured by the cubic foot or cubic metre, but is billed like electricity by the
kilowatt hour
.
[49]
Pre-packaged products can show both metric and imperial measures, and it is also common to see imperial pack sizes with metric only labels, e.g. a 1 lb (454 g) tin of Lyle's Golden Syrup is always labelled
454 g
with no imperial indicator. Similarly most jars of jam and packs of sausages are labelled
454 g
with no imperial indicator.
India
[
edit
]
India
began converting to the metric system from the imperial system between 1955 and 1962. The metric system in weights and measures was adopted by the
Indian Parliament
in December 1956 with the
Standards of Weights and Measures Act
, which took effect beginning 1 October 1958. By 1962, metric units became "mandatory and exclusive."
[50]
Today all official measurements are made in the metric system. In common usage some older Indians may still refer to imperial units. Some measurements, such as the heights of mountains, are still recorded in feet. Tyre rim diameters are still measured in inches, as used worldwide. Industries like the construction and the real estate industry still use both the metric and the imperial system though it is more common for sizes of homes to be given in square feet and land in acres.
[51]
In
Standard Indian English
, as in
Australian
,
Canadian
,
New Zealand
,
Singaporean
, and
British English
, metric units such as the litre, metre, and
tonne
utilise the traditional spellings brought over from
French
, which differ from those used in the
United States
and the
Philippines
. The imperial long ton is invariably spelt with one 'n'.
[51]
Hong Kong
[
edit
]
Hong Kong
has three main systems of
units of measurement
in current use:
In 1976 the
Hong Kong Government
started the conversion to the metric system, and as of 2012 measurements for government purposes, such as road signs, are almost always in metric units. All three systems are officially permitted for trade,
[52]
and in the wider society a mixture of all three systems prevails.
The Chinese system's most commonly used units for length are
里
(
lei
5
),
丈
(
zoeng
6
),
尺
(
cek
3
),
寸
(
cyun
3
),
分
(
fan
1
) in descending scale order. These units are now rarely used in daily life, the imperial and metric systems being preferred. The imperial equivalents are written with the same basic Chinese characters as the Chinese system. In order to distinguish between the units of the two systems, the units can be prefixed with "Ying" (
英
,
jing
1
) for the imperial system and "Wa" (
華
,
waa
4
) for the Chinese system. In writing, derived characters are often used, with an additional
口
(mouth)
radical
to the left of the original Chinese character, for writing imperial units. The most commonly used units are the
mile
or "li" (
?
,
li
1
), the
yard
or "ma" (
碼
,
maa
5
), the
foot
or "chek" (
?
,
cek
3
), and the
inch
or "tsun" (
?
,
cyun
3
).
The traditional measure of flat area is the square foot (
方?, 平方?
,
fong
1
cek
3
, ping
4
fong
1
cek
3
) of the imperial system, which is still in common use for real estate purposes. The measurement of agricultural plots and fields is traditionally conducted in
畝
(
mau
5
) of the Chinese system.
For the measurement of volume, Hong Kong officially uses the metric system, though the gallon (
加侖
,
gaa
1
leon
4-2
) is also occasionally used.
Canada
[
edit
]
A one US gallon gas can purchased near the US-Canada border showing equivalences in imperial gallons and litres
Imperial and metric measurements on Canadian canned goods labels. The imperial measurements often take precedence over the metric ones on labels.
During the 1970s, the metric system and SI units were introduced in Canada to replace the imperial system. Within the government, efforts to implement the metric system were extensive; almost any agency, institution, or function provided by the government uses SI units exclusively. Imperial units were eliminated from all public road signs and both systems of measurement will still be found on privately owned signs, such as the height warnings at the entrance of a
parkade
. In the 1980s, momentum to fully convert to the metric system stalled when the government of
Brian Mulroney
was elected. There was heavy opposition to metrication and as a compromise the government maintains legal definitions for and allows use of imperial units as long as metric units are shown as well.
[53]
[54]
[55]
[56]
The law requires that measured products (such as fuel and meat) be priced in metric units and an imperial price can be shown if a metric price is present.
[57]
[58]
There tends to be leniency in regards to fruits and vegetables being priced in imperial units only.
Environment Canada
still offers an imperial unit option beside metric units, even though weather is typically measured and reported in metric units in the Canadian media. Some radio stations near the United States border (such as
CIMX
and
CIDR
) primarily use imperial units to report the weather. Railways in Canada also continue to use imperial units.
Imperial units are still used in ordinary conversation. Today, Canadians typically use a mix of metric and imperial measurements in their daily lives. The use of the metric and imperial systems varies by age. The older generation mostly uses the imperial system, while the younger generation more often uses the metric system.
Quebec
has implemented metrication more fully.
[
citation needed
]
Newborns are measured in SI at hospitals, but the birth weight and length is also announced to family and friends in imperial units. Drivers' licences use SI units, though many English-speaking Canadians give their height and weight in imperial. In livestock auction markets, cattle are sold in dollars per
hundredweight
(short), whereas hogs are sold in dollars per hundred kilograms. Imperial units still dominate in recipes, construction, house renovation and gardening.
[59]
[60]
[61]
[62]
[63]
Land is now surveyed and registered in metric units whilst initial surveys used imperial units. For example, partitioning of farmland on the prairies in the late 19th and early 20th centuries was done in imperial units; this accounts for imperial units of distance and area retaining wide use in the
Prairie Provinces
.
In English-speaking Canada commercial and residential spaces are mostly (but not exclusively) constructed using square feet, while in French-speaking Quebec commercial and residential spaces are constructed in metres and advertised using both square metres and square feet as equivalents. Carpet or flooring tile is purchased by the square foot, but less frequently also in square metres.
[64]
[65]
Motor-vehicle fuel consumption is reported in both litres per
100 km
and statute miles per imperial gallon,
[66]
leading to the erroneous impression that Canadian vehicles are 20% more fuel-efficient than their apparently identical American counterparts for which fuel economy is reported in statute miles per US gallon (neither country specifies which gallon is used). Canadian railways maintain exclusive use of imperial measurements to describe train length (feet), train height (feet), capacity (
tons
), speed (mph), and trackage (miles).
[67]
Imperial units also retain common use in firearms and ammunition. Imperial measures are still used in the description of cartridge types, even when the cartridge is of relatively recent invention (e.g.,
.204 Ruger
,
.17 HMR
, where the calibre is expressed in decimal fractions of an inch). Ammunition that is already classified in metric is still kept metric (e.g.,
9×19mm
). In the manufacture of ammunition, bullet and powder weights are expressed in terms of
grains
for both metric and imperial cartridges.
In keeping with the international standard, air navigation is based on
nautical
units, e.g., the nautical mile, which is neither imperial nor metric, and altitude is measured in imperial feet.
[68]
Australia
[
edit
]
While metrication in Australia has largely ended the official use of imperial units, for particular measurements, international use of imperial units is still followed.
- In licensed venues, draught beer and cider is sold in glasses and jugs with
sizes
based on the imperial fluid ounce, though rounded to the nearest 5 mL.
- Newborns are measured in metric at hospitals, but the birth weight and length is sometimes also announced to family and friends in imperial units.
- Screen sizes, are frequently advertised in inches instead of or as well as centimetres.
- Property size is frequently advertised in acres, but is mostly as square metres.
- Navigation is done in nautical miles, and water-based speed limits are in nautical miles per hour.
- Historical writing and presentations may include pre-metric units to reflect the context of the era represented.
- The illicit drug trade in Australia still often uses imperial measurements, particularly when dealing with smaller amounts closer to end user levels e.g. "8-ball" an 8th of an ounce or
3.5 g
; cannabis is often traded in ounces ("oz") and pounds ("p")
[
citation needed
]
- Firearm barrel length are almost always referred by in inches, ammunition is also still measured in grains and ounces as well as grams.
The influence of British and American culture in Australia has been noted to be a cause for residual use of imperial units of measure.
New Zealand
[
edit
]
New Zealand introduced the metric system on 15 December 1976.
[69]
Aviation was exempt, with altitude and airport elevation continuing to be measured in feet whilst navigation is done in
nautical miles
; all other aspects (fuel quantity, aircraft weight, runway length, etc.) use metric units.
Screen sizes for devices such as televisions, monitors and phones, and wheel rim sizes for vehicles, are stated in inches, as is the convention in the rest of the world - and a 1992 study found a continued use of imperial units for birth weight and human height alongside metric units.
[70]
Ireland
[
edit
]
Ireland has officially changed over to the metric system since entering the
European Union
, with distances on new road signs being metric since 1997 and speed limits being metric since 2005. The imperial system remains in limited use ? for sales of beer in pubs (traditionally sold by the pint). All other goods are required by law to be sold in metric units with traditional quantities being retained for goods like butter and sausages, which are sold in 454 grams (1 lb) packaging. The majority of cars sold pre-2005 feature speedometers with miles per hour as the primary unit, but with a kilometres per hour display. Often signs such as those for bridge height can display both metric and imperial units. Imperial measurements continue to be used colloquially by the general population especially with height and distance measurements such as feet, inches, and acres as well as for weight with pounds and stones still in common use among people of all ages. Measurements such as yards have fallen out of favour with younger generations. Ireland's railways still use imperial measurements for distances and speed signage.
[71]
[72]
Property is usually listed in square feet as well as metres also.
Horse racing in Ireland still continues to use stones, pounds, miles and furlongs as measurements.
[73]
Bahamas
[
edit
]
Imperial measurements remain in general use in the
Bahamas
.
Legally, both the imperial and metric systems are recognised by the Weights and Measures Act 2006.
[74]
Belize
[
edit
]
Both imperial units and metric units are used in
Belize
. Both systems are legally recognized by the National Metrology Act.
[75]
Myanmar
[
edit
]
According to the CIA, in June 2009, Myanmar was one of three countries that had not adopted the
SI metric system
as their official system of weights and measures.
[76]
[
unreliable source?
]
Metrication efforts began in 2011.
[77]
The
Burmese government
set a goal to metricate by 2019, which was not met, with the help of the
German National Metrology Institute
.
[78]
Other countries
[
edit
]
Some imperial measurements remain in limited use in
Malaysia
, the
Philippines
,
Sri Lanka
and
South Africa
. Measurements in feet and inches, especially for a person's height, are frequently encountered in conversation and non-governmental publications.
Prior to metrication, it was a common practice in Malaysia for people to refer to unnamed locations and small settlements along major roads by referring to how many miles the said locations were from the nearest major town. In some cases, these eventually became the official names of the locations; in other cases, such names have been largely or completely superseded by new names. An example of the former is Batu 32 (literally "Mile 32" in
Malay
), which refers to the area surrounding the intersection between
Federal Route 22
(the
Tamparuli
-
Sandakan
highway) and
Federal Route 13
(the Sandakan-
Tawau
highway). The area is so named because it is 32 miles west of Sandakan, the nearest major town.
Petrol is still sold by the imperial gallon in
Anguilla
,
Antigua and Barbuda
,
Belize
,
Myanmar
, the
Cayman Islands
,
Dominica
,
Grenada
,
Montserrat
,
St Kitts and Nevis
and
St. Vincent and the Grenadines
.
[
citation needed
]
The
United Arab Emirates
Cabinet in 2009 issued the Decree No. (270 / 3) specifying that, from 1 January 2010, the new unit sale price for petrol will be the litre and not the gallon, which was in line with the UAE Cabinet Decision No. 31 of 2006 on the national system of measurement, which mandates the use of International System of units as a basis for the legal units of measurement in the country.
[79]
[80]
[81]
[82]
Sierra Leone switched to selling fuel by the litre in May 2011.
[83]
In October 2011, the Antigua and Barbuda government announced the re-launch of the Metrication Programme in accordance with the Metrology Act 2007, which established the International System of Units as the legal system of units. The Antigua and Barbuda government has committed to a full conversion from the imperial system by the first quarter of 2015.
[84]
See also
[
edit
]
Explanatory notes
[
edit
]
Citations
[
edit
]
- ^
Britannica Educational Publishing (2010).
The Britannica Guide to Numbers and Measurement
. The Rosen Publishing Group. p. 241.
ISBN
978-1-61530-218-5
.
Archived
from the original on 14 January 2023
. Retrieved
1 July
2015
.
- ^
Chaney, Henry James (1897).
A Practical Treatise on the Standard Weights and Measures in Use in the British Empire with some account of the metric system
. Eyre and Spottiswoode. p.
3
. Retrieved
11 September
2016
.
- ^
"Weights and Measures Act 1985"
.
legislation.gov.uk
.
Archived
from the original on 2 January 2022
. Retrieved
20 January
2020
.
- ^
a
b
c
Great Britain (1824).
The statutes of the United Kingdom of Great Britain and Ireland (1807-1865)
. His Majesty's statute and law printers. pp.
339
?354
. Retrieved
31 December
2011
.
- ^
Great Britain;
William David Evans
; Anthony Hammond; Thomas Colpitts Granger (1836).
A collection of statutes connected with the general administration of the law: arranged according to the order of subjects
. W. H. Bond. pp.
306
?27
. Retrieved
31 December
2011
.
- ^
Edinburgh medical and surgical journal
. A. and C. Black. 1824. p. 398.
- ^
Ireland; Butler, James Goddard; Ball, William (barrister.) (1765).
The Statutes at Large, Passed in the Parliaments Held in Ireland: From the twenty-third year of George the Second, A.D. 1749, to the first year of George the Third, A.D. 1761 inclusive
. Boulter Grierson. p. 852.
- ^
Gray, Samuel Frederick
(1836).
A supplement to the Pharmacopœia and treatise on pharmacology in general: including not only the drugs and preparations used by practitioners of medicine, but also most of those employed in the chemical arts : together with a collection of the most useful medical formulæ ...
Longman, Rees, Orme, Brown, Green, and Longman. p.
516
. Retrieved
29 July
2012
.
- ^
"A Translation of the Pharmacopoeia of the Royal College of Physicians of London, 1836.: With ..."
S. Highley, 32, Fleet Street. 1837.
- ^
The Pharmacopoeia of the Royal College of Physicians of Edinburgh
. Adam and Charles Black and Bell and Bradfute. 1839. pp. xiii?xiv.
- ^
Royal College of Physicians of Dublin;
Royal College of Physicians of Ireland
(1850).
The pharmacopœia of the King and queen's college of physicians in Ireland
. Hodges and Smith. p. xxii
. Retrieved
29 July
2012
.
- ^
Great Britain (1858).
A collection of the public general statutes passed in the ... year of the reign of ...
Printed by G. W. Eyre and W. Spottiswoode, Printers to the Queen. p. 306.
- ^
Sears et al. 1928.
Phil Trans A
, 227:281.
- ^
Jerrard and McNeill, Dictionary of Scientific Units, second edition, Chapman and Hall; cites first appearance in print in Journal of the Institution of Electrical Engineers (G.B.) vol. 1, page 246 (1872).
- ^
The exact figure was
6.08 ft
, but
6 ft
was in use in practice. The commonly accepted definition of a fathom was always 6 feet. The conflict was inconsequential, as Admiralty nautical charts designated depths shallower than
5 fathoms
in feet on older imperial charts. Today, all charts worldwide are metric, except for USA Hydrographic Office charts, which use feet for all depth ranges.
- ^
The
nautical mile
was not readily expressible in terms of any of the intermediate units, because it was derived from the circumference of the Earth (like the original metre).
- ^
"Appendix C: General Tables of Units of Measurements"
(PDF)
. NIST. Archived from
the original
(PDF)
on 26 November 2006
. Retrieved
4 January
2007
.
- ^
a
b
c
"An Act for ascertaining and establishing Uniformity of Weights and Measures (17 June 1824)"
(PDF)
.
legislation.gov.uk
. 17 June 1824. p. 639,640.
Archived
(PDF)
from the original on 20 July 2020
. Retrieved
19 January
2020
.
Two such Gallons shall be a Peck, and Eight such Gallons shall be a Bushel, and Eight such Bushels a Quarter of Corn or other dry Goods, not measured by Heaped Measure.
. (The date of coming into effect was 1 May 1825).
- ^
imperial gallon
. Sizes.com. 25 October 2013.
Archived
from the original on 14 May 2011
. Retrieved
10 July
2019
.
- ^
"The Weights and Measures (Equivalents for dealings with drugs) Regulations 1970"
.
Archived
from the original on 20 June 2013
. Retrieved
7 July
2012
.
- ^
"Information Sheet: 11: Balances, Weights and Measures"
(PDF)
.
Royal Pharmaceutical Society
.
Archived
(PDF)
from the original on 20 May 2022
. Retrieved
11 December
2020
.
- ^
a
b
Zentz, Lorraine C. (2010).
"Chapter 1: Fundamentals of Math ? Apothecary System"
.
Math for Pharmacy Technicians
. Sudbury, MA:
Jones & Bartlett Learning
. pp. 7?8.
ISBN
978-0-7637-5961-2
.
OCLC
421360709
.
Archived
from the original on 14 January 2023
. Retrieved
1 July
2015
.
- ^
a
b
Boyer, Mary Jo (2009).
"UNIT 2 Measurement Systems: The Apothecary System"
.
Math for Nurses: A Pocket Guide to Dosage Calculation and Drug Preparation
(7th ed.). Philadelphia, PA:
Wolters Kluwer Health
|
Lippincott Williams & Wilkins
. pp. 108?9.
ISBN
978-0-7817-6335-6
.
OCLC
181600928
.
Archived
from the original on 14 January 2023
. Retrieved
1 July
2015
.
- ^
a
b
c
Royal College of Physicians of Dublin
(1850). "Weights and Measures".
The Pharmacopœia of the King and Queen's College of Physicians in Ireland
. Dublin: Hodges and Smith. p. xlvi.
hdl
:
2027/mdp.39015069402942
.
OCLC
599509441
.
- ^
a
b
c
National Institute of Standards and Technology (October 2011). Butcher, Tina; Cook, Steve; Crown, Linda et al. eds.
"Appendix C ? General Tables of Units of Measurement"
Archived
17 June 2016 at the
Wayback Machine
(PDF).
Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices
Archived
3 June 2016 at the
Wayback Machine
. NIST Handbook.
44
(2012 ed.). Washington, D.C.: US Department of Commerce, Technology Administration, National Institute of Standards and Technology.
ISSN
0271-4027
Archived
25 December 2022 at the
Wayback Machine
.
OCLC
OCLC
58927093
. Retrieved 6 July 2012.
- ^
a
b
Rowlett, Russ (13 September 2001).
"F"
.
How Many? A Dictionary of Units of Measurement
. Chapel Hill, NC:
University of North Carolina at Chapel Hill
. fluid dram or fluidram (fl dr). Archived from
the original
on 9 July 2018
. Retrieved
6 July
2012
.
- ^
Buchholz, Susan; Henke, Grace (2009).
"Chapter 3: Metric, Apothecary, and Household Systems of Measurement ? Table 3-1: Apothecary Abbreviations"
.
Henke's Med-Math: Dosage Calculation, Preparation and Administration
(6th ed.). Philadelphia, PA:
Wolters Kluwer Health
|
Lippincott Williams & Wilkins
. p. 55.
ISBN
978-0-7817-7628-8
.
OCLC
181600929
.
Archived
from the original on 14 January 2023
. Retrieved
1 July
2015
.
- ^
Pickar, Gloria D.; Swart, Beth; Graham, Hope; Swedish, Margaret (2012).
"Appendix B: Apothecary System of Measurement ? Apothecary Units of Measurement and Equivalents"
.
Dosage Calculations
(2nd Canadian ed.). Toronto: Nelson Education. p. 528.
ISBN
978-0-17-650259-1
.
OCLC
693657704
.
Archived
from the original on 14 January 2023
. Retrieved
1 July
2015
.
- ^
United Kingdom
;
Department of Trade and Industry
(1995).
The Units of Measurement Regulations 1995
. London:
HMSO
. Schedule: Relevant Imperial Units, Corresponding Metric Units and Metric Equivalents.
ISBN
978-0-11-053334-6
.
OCLC
33237616
.
Archived
from the original on 19 December 2021
. Retrieved
1 July
2012
.
- ^
Great Britain (1878).
Statutes at large ...
p. 308.
- ^
Chaney, Henry James (1911).
"Weights and Measures"
. In
Chisholm, Hugh
(ed.).
Encyclopædia Britannica
. Vol. 28 (11th ed.). Cambridge University Press. pp. 477?494, see page 480.
- ^
a
b
Great Britain (1855).
A collection of public general statutes passed in the 18th and 19th years of the reign of Her Majesty Queen Victoria
. pp. 273?75.
- ^
"The Units of Measurement Regulations 1994"
.
legislation.gov.uk
.
Archived
from the original on 25 February 2021
. Retrieved
13 March
2019
.
- ^
"Definition of stone in English from the Oxford dictionary"
.
www.oxforddictionaries.com
. Oxford University Press. Archived from
the original
on 11 July 2012
. Retrieved
25 November
2015
.
- ^
"Bulk densities of some common food products"
.
engineeringtoolbox.com
.
Archived
from the original on 5 July 2020
. Retrieved
19 January
2020
.
The density of wheat is 0.770, and 291*0.770=224 kilograms (494 lb).
- ^
a
b
Weights and Measures Act
Archived
16 October 2012 at the
Wayback Machine
- ^
"Wolfram-Alpha: Computational Knowledge Engine"
.
Archived
from the original on 14 January 2023
. Retrieved
23 June
2015
.
- ^
a
b
Kelly, Jon (21 December 2011).
"Will British people ever think in metric?"
. BBC.
Archived
from the original on 24 April 2012
. Retrieved
26 February
2017
.
...but today the British remain unique in Europe by holding onto imperial weights and measures. ...the persistent British preference for imperial over metric is particularly noteworthy...
- ^
"Height and width road signs to display metric and imperial"
. BBC. 8 November 2014.
Archived
from the original on 26 February 2017
. Retrieved
26 February
2017
.
New road signs showing height and width restrictions will use both metric and imperial measurements from March 2015....Road signs for bridges, tunnels and narrow roads can currently show measurements in just feet and inches or only metres. Some already display both.
- ^
"BusinessLink: Weights and measures: Rules for pubs, restaurants and cafes"
. Department for Business, Innovation & Skills. Archived from
the original
(online)
on 20 July 2011
. Retrieved
24 August
2009
.
- ^
"Department for Transport statement on metric road signs"
(online)
. BWMA. 12 July 2002.
Archived
from the original on 25 May 2009
. Retrieved
24 August
2009
.
- ^
"In praise of ... metric measurements"
.
The Guardian
. London. 1 December 2006.
Archived
from the original on 19 September 2017
. Retrieved
29 October
2017
.
- ^
King, Max (15 February 2021).
"Decimalisation: Britain's "new pence" turn 50 years old"
.
MoneyWeek
.
Archived
from the original on 15 May 2021
. Retrieved
8 April
2021
.
- ^
"BMI healthy weight calculator"
.
National Health Service
.
Archived
from the original on 19 January 2016
. Retrieved
25 November
2015
.
- ^
Dahlgreen, Will (20 June 2015).
"Britain's metric muddle not changing any time soon"
.
Archived
from the original on 30 October 2017
. Retrieved
29 October
2017
.
even today [2015] some 18-24-year-olds still do not know how much they weigh in kilograms (60%) or how tall they are in metres and centimetres (54%).
- ^
"YouGov Survey Results"
(PDF)
. 2015.
Archived
(PDF)
from the original on 30 October 2017
. Retrieved
29 October
2017
.
- ^
"Weights and measures: the law"
.
gov.uk
. 7 April 2020.
Archived
from the original on 2 October 2015
. Retrieved
7 April
2020
.
- ^
"Explanatory memorandum to The weights and measures (metrication amendments) regulations 2009"
(PDF)
.
Legislation.gov.uk
. 2009.
Archived
(PDF)
from the original on 4 March 2021
. Retrieved
3 November
2019
.
See paragraph 7.4.
- ^
"Gas meter readings and bill calculation"
.
gov.uk
.
Archived
from the original on 20 December 2016
. Retrieved
15 December
2016
.
- ^
Velkar, Ashish (May 2018).
"Rethinking Metrology, Nationalism and Development in India, 1833?1956"
(PDF)
.
Past & Present
(239): 143?79.
doi
:
10.1093/pastj/gtx064
.
Archived
(PDF)
from the original on 29 May 2022
. Retrieved
30 April
2022
.
- ^
a
b
Acharya, Anil Kumar.
History of Decimalisation Movement in India
, Auto-Print & Publicity House, 1958.
- ^
"CAP 68 WEIGHTS AND MEASURES ORDINANCE Sched 2 UNITS OF MEASUREMENT AND PERMITTED SYMBOLS OR ABBREVIATIONS OF UNITS OF MEASUREMENT LAWFUL FOR USE FOR TRADE"
.
Archived
from the original on 3 September 2015
. Retrieved
31 January
2015
.
- ^
"Weights and Measures Act: Canadian units of measure"
. Justice Canada. Archived from
the original
on 5 June 2011
. Retrieved
14 November
2007
.
- ^
"11"
.
Guide to Food Labelling and Advertising
.
Canadian Food Inspection Agency
. Archived from
the original
on 24 January 2008
. Retrieved
1 December
2007
.
- ^
"Consumer Packaging and Labelling Regulations (C.R.C., c. 417)"
. Justice Canada, Legislative Services Branch.
Archived
from the original on 27 December 2012
. Retrieved
15 November
2012
.
- ^
"Field Inspection Manual ? Automatic Weighing Devices: Part 3, Section A: Abbreviations and Symbols Accepted in Canada"
. 2 February 2017.
Archived
from the original on 26 August 2022
. Retrieved
21 July
2022
.
- ^
"A Canadian compromise"
.
CBC
. 30 January 1985. Archived from
the original
on 16 January 2009
. Retrieved
11 March
2008
.
- ^
"Les livres et les pieds, toujours presents (eng:The pounds and feet, always present)"
(in French). 5 sur 5, Societe
Radio-Canada
. Archived from
the original
on 6 June 2011
. Retrieved
11 March
2008
.
- ^
"Imperial Measures - The Origins"
.
BWMAOnline.com
.
British Weights and Measures Association
. 15 February 2021.
Archived
from the original on 15 May 2011
. Retrieved
5 March
2011
.
- ^
Rosen, Amy (23 February 2011).
"Crepes worth savouring"
.
National Post
.
Archived
from the original on 11 July 2019
. Retrieved
11 July
2019
– via PressReader.com.
- ^
Rosen, Amy (2 February 2011).
"Scoring brownie points"
.
National Post
.
Archived
from the original on 11 July 2019
. Retrieved
11 July
2019
– via PressReader.com.
- ^
McDowell, Adam (28 February 2011).
"Drinking school"
.
National Post
.
- ^
"Home Hardware - Building Supplies - Building Materials - Fence Products"
. Archived from
the original
on 29 June 2011
. Retrieved
5 March
2011
.
- ^
"Canada: Metric System"
.
Archived
from the original on 13 February 2020
. Retrieved
24 February
2020
.
- ^
Allard, Marie (25 August 2015).
"Systeme metrique: a quand le virage final?"
.
LaPresse.ca
(in French).
Archived
from the original on 24 February 2020
. Retrieved
24 February
2020
.
- ^
Canada, Government of Canada, Natural Resources.
"Fuel Consumption Ratings Search Tool - Conventional Vehicles"
. Archived from
the original
on 6 July 2011
. Retrieved
15 January
2009
.
{{
cite web
}}
: CS1 maint: multiple names: authors list (
link
)
- ^
Canada, Government of Canada, Transportation Safety Board of (9 April 1999).
"Railway Investigation Report R96W0171"
.
Archived
from the original on 6 July 2011
. Retrieved
5 March
2011
.
{{
cite web
}}
: CS1 maint: multiple names: authors list (
link
)
- ^
"Canadian Aviation Regulations"
.
Langley Flying School
. sec. "Altimeter Rules".
Archived
from the original on 14 May 2014
. Retrieved
14 May
2014
.
- ^
"
"30 Years of the Metric System"
"
.
Archived
from the original on 9 February 2021
. Retrieved
4 February
2021
.
- ^
"Human use of metric measures of length"
Archived
9 February 2013 at the
Wayback Machine
. Dignan, J. R. E., & O'Shea, R. P. (1995). New Zealand Journal of Psychology,
24
, 21?25.
- ^
"Republic of Ireland"
. www.railsigns.uk. Archived from
the original
on 23 October 2021
. Retrieved
22 February
2021
.
- ^
"Network Statement 2022"
(PDF)
.
Irish Rail
.
Archived
(PDF)
from the original on 19 January 2022
. Retrieved
24 February
2022
.
- ^
"Full HRI Directives"
. Archived from
the original
on 4 May 2016.
- ^
Parliament of the Bahamas.
"Weights and Measures Act 2006"
.
Bahamas Bureau of Standards and Quality
.
Archived
from the original on 2 June 2021
. Retrieved
24 September
2021
.
- ^
"National Metrology Act, Chapter 294, Revised Edition 2011"
(PDF)
. Government of Belize
. Retrieved
11 January
2024
.
- ^
"The World Factbook, Appendix G: Weights and Measures"
.
Web Pages
. Central Intelligence Agency. 2010. Archived from
the original
on 28 May 2010
. Retrieved
10 May
2010
.
- ^
Gyi, Ko Ko (18?24 July 2011).
"Ditch the viss, govt urges traders"
. Business and Property.
The Myanmar Times
. Translated by Thit Lwin. Myanmar. Archived from
the original
on 20 September 2011
. Retrieved
4 March
2023
.
- ^
Kohler, Nicholas (3 March 2014).
"Metrication in Myanmar"
.
Mizzima News
. Archived from
the original
on 16 December 2014
. Retrieved
20 April
2015
.
- ^
"Address by Agriculture Minister Gregory Bowen"
. The Ministry of Agriculture,
Government of Grenada
. 1 November 2004. Archived from
the original
on 24 March 2008
. Retrieved
15 January
2008
.
The price of gasoline at the pumps was fixed at EC$7.50 per imperial gallon...
- ^
"FAQ"
.
MoF.gov.bz
. Belize Ministry of Finance. Archived from
the original
on 23 January 2008
. Retrieved
15 January
2008
.
? Kerosene per US Gallon (per Imperial gallon) ? Gasoline (Regular)(per imperial Gallon) ? Gasoline (Premium) (per Imperial Gallon) ? Diesel (per Imperial Gallon)
- ^
"The High Commission Antigua and Barbuda"
. Archived from
the original
on 31 January 2009
. Retrieved
15 January
2008
.
- ^
Metschies, Gerhard P. (6 September 2005).
"International Fuel Prices 2005"
(PDF)
.
International-Fuel-Prices.com
. German Technical Cooperation. p. 96. Archived from
the original
(PDF)
on 7 February 2007
. Retrieved
15 January
2008
.
- ^
"Introduction of the Metric System and the Price of Petroleum Products"
.
Sierra Leone
Embassy in the United States. Archived from
the original
on 29 April 2015
. Retrieved
23 October
2011
.
- ^
"Minister Lovell Addresses Metric Conversions"
.
CARIBARENA Antigua
. 18 October 2011. Archived from
the original
on 20 October 2011
. Retrieved
23 October
2011
.
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