If I have to make survey measurements and/or do calculations, I’d always use the metric system: metres, hectares, cubic metres, kilos and litres etc. Just so much easier. Yet if you asked me the distance to anywhere in Ireland, I’d think in miles. Driving there, as regards speed I’d think in KPH. Personal weight and height – stones, feet & inches. Farms – so many acres of land. Buy pints of stout and litres of milk.
I reckon I’m not untypical – we may have adopted the metric system more fully than our British neighbours but we’re still pretty inconsistent. You measure your kitchen in square metres, go to the tile showroom and they’ve everything priced in square yards. What’s even more daft is that the same tiles are usually imported from other EU countries in handy boxes each containing 1 square metre. Whence they’ll break up the boxes as 1 square yard is 0.836127 square metres. Daft!
For anyone sufficiently bored and/or nerdy to be bothered / interested in such things, I’ve written up a random list of how some common and uncommon measurements relate to each other: chains, furlongs & acres, naggins and pints.
1 metre = 3.281 feet, 1 foot = 0.3047 metres
1 mile = 1.609 kilometres, 1 kilometre = 0.62 mile
1 mile = 1760 yards but an Irish mile is 2240 yards
1 chain = 66 feet, 10 chains = 1 furlong and 80 chains = 1 mile
40 perch poles = 1 furlong, 8 furlongs = 1 mile and 3 miles = 1 league.
Then there’s the knot or nautical mile (they have to be different) which is approx. 1.151 miles. But there’s a method to their madness as 1 knot is equal to 1 minute of arc of the earths circumference (360o x 60’ = 21,600 nautical miles = round the world!)
1 hectare = 100 metres x 100 metres – dead handy😊 100 hectares = 1 square kilometre. 1 square kilometre – that handy grid printed on your map.
1 acre = 0.4041 hectare, 1 hectare = 2.47 acres
1 acre = 10 square chains or 1 furlong x 1 chain = 4840 square yards.
40 square perches = 1 rood and 4 roods = 1 acre (old maps & documents often list areas in ‘arp’: acres, roods and perches).
1 Irish acre = 1.6198 acres but a Cunningham/ Conyingham (Scottish) acre is only 1.29 acres.
1 litre = 1000 cubic centimetres = 1 kilogram at standard density of water (handy to know).
1 gallon = 4.54 litres.
4 naggins (handy for buying the whiskey) = 1 pint, 2 pints = 1 quart, 4 quarts to the gallon.
2 gallons = 1 peck, 4 pecks = 1 bushel and 4 bushels = 1 barrel!
16 drachm = 1 ounce, 16 ounces to the lb, 14 lbs to the stone, 8 stone to the hundredweight (cwt, 112 lbs), 20 cwt to the ton. 1 ton (2240 lbs) is a little heavier than 1 metric ton (1000 kilograms or 2204 lbs). A bag of cement used to be 1 cwt (c 51kgs), then it was reduced to 40kg, now it’s usually 25kg – we must be getting weaker!!