# Units

“For when I gave you an inch, you took an ell.” / *John Heywood, 1546*

The reach of Science Village is becoming wider and wider. Recently Ulrika Lindmark was invited to present our plans to a group of industrialists in London. Naturally Ulrika asked me beforehand which side of the road do people drive on, but more particularly when describing our set up should we be quoting land area in hectares or acres. Well, anyone who is following the debate on the UK’s place in the EU will realise that there are certain things that are sacrosanct in the UK so one has to tread carefully when it comes to units. In what follows I give a slightly tongue in cheek overview of units in Britain.

Yes, Britain still uses so-called Imperial Units like miles, gallons, pints, pounds weight etc. And we still drive on the left-hand side of the road 🙂 There is a “good” reason for this, which is related to which side of your body is your heart, which side you wear your sword and whether you are right-handed. All this leads to mounting your horse from the left side and continuing to ride on the left. It of course makes complete sense and the tradition has transferred to aeroplanes and ships where access is always from the left. When did you ever board a plane from the right hand side…?

However, throwing caution to the wind, I advised Ulrika to stick to the metric system; Napoleon got it right. He defined the distance from the North Pole to the equator as being precisely 10,000 km, which then set the value of the metre. Use square metres and hectares for areas, I advised, metres and kilometres for lengths, and kilograms and tonnes for weights, as well as litres for liquids. Professionals in the UK almost always work in metric units simply because they have to interact with other countries. If you were talking to industrialists in the USA it might be different.

Conveniently a yard is roughly a metre (10% less in fact) so square yards and square metres are rather close (20% less). 3 feet is one yard (of course!). So there are approximately 10 square feet in one square metre. A foot is the length of a man’s foot and a yard is the length of a man’s step (normally the King himself was used as the standard). This is an easy conversion factor. Estate agents prefer to use square feet than square yards or square metres since you can think that you get more floor area for your money when building units are quoted in square feet.

Land area is almost always quoted in acres, again you appear to get more for your money than using hectares. One hectare is approximately two acres so SVS is ~35 acres in area, far bigger, psychologically, than 18 hectares. An Imperial ton (2240 pounds) is very close to a metric tonne (1000kg). Why 2240? Well 16 ounces make one pound, 14 pounds make one stone, 2 stones make one quarter, 4 quarters make one hundredweight, and 20 hundredweights make one ton. Which comes to 2240. So it’s quite simple. When it does get difficult however is when, as a school pupil, you are given maths questions like “a farmer has 17 sheep which on average weigh 7 stone 12 pounds. He sells the sheep at market and gets 43 pounds, 12 shilling and sixpence for each sheep. How much does one pound of mutton cost?” Of course, just to avoid confusion, the unit of weight and the unit of currency have the same name.

People still quote their weight in stones and pounds and their height in feet and inches. And, of course, 8 pints make 1 gallon (a pint is the unit for milk and beer although, shockingly, petrol is nowadays dispensed in litres! But the petrol consumption of a car is still quoted as so many miles per gallon). 1.8 pints is one litre by the way. Half a litre is not equal to one pint as beer drinkers will be quick to tell you, should you be so unwise to suggest that it is even close. How can you possibly quench your thirst with half a litre of beer. It’s unnatural.

And lawyers charge for their time in guineas. A golden guinea, which existed as a coin, was 21 shillings whereas a pound was only 20 shillings. Therefore by charging in guineas instead of pounds lawyers magically got 5% more whereas you, as the client, didn’t even notice. Gold coins of one pound value are still minted of course – they are called sovereigns…

Oh, I forgot – 12 inches is 1 foot. And horses are measured in hands. A hand is 4 inches.

Finally, every English schoolboy knows that a cricket pitch is 22 yards long. 22 yards is 1 chain. 10 chains is one furlong. 8 furlongs is one mile. That means that 1 mile is 1760 yards. Roger Bannister was the first person to run a mile in under 4 minutes – every schoolboy used to know that as well, but the Olympics have ruined that. A furlong is the length of a ploughed furrow. Oh, and while we are talking about cricket, there are 6 balls in an over, unless you live in Australia of course, where it was 8 balls in an over. Schoolgirls have got more sense. Will we have a cricket pitch at Science Village? Well it is not out of the question – there is certainly enough land and I have a cricket ball in my socks drawer! See below.

All we need now are two cricket bats, two sets of stumps and four bails. Easy really 🙂

And, armed with this knowledge, without even mentioning foot-candle or horsepower, off went Ulrika to London and came back very successfully. She still drives on the right hand side of the road however!

*By the way, the ell of the quotation at the top of the article, refers to the distance from the tip of your fingers to your elbow. Elbow is of course the point where the forearm bends or “bows”. The ell was used by many countries and varied enormously.*

**UNITS, conversion to the metric system **(Wikipedia)

**Length**

inch (in) = 25,4 mm

foot (ft) = 12 in = 0,3 m

yard (yd) = 3 ft = 36 in = 0,9 m

mile = 5 280 ft = 1 609,3 m

ell = 45 inch, eller 1,1 meter (UK)

**Square measure**

square inch (in², sq in) = 6,45 cm²

square foot (ft², sq ft) = 0,09 m²

square yard (yd², sq yd) = 0,84 m²

acre = 4 840 yd² ≈ 4 046,86 m2

square mile (mile²) = 640 acres ≈ 2,59 km²

**Volume**

gallon (gal): 4,546 dm³ (UK)

pint (pt) = 1/8 gal (UK) = 0,568 dm³ (UK)

**Weight**

pound (lb) = 0,45 kg

ounce (oz) = 1/16 lb ≈ 28,35 g

stone = 14 lb = 6,35 kg

hundredweight (cwt): 1 cwt (UK) = 1 long cwt (US) = 112 lb ≈ 50,80 kg

ton: 1 ton (UK) = 1 long ton (US) = 2 240 lb ≈ 1 016,05 kg