Really? First, the Imperial gallon is 4 imperial quarts which is 4 liters. The only reason America is different, is because when the British government (we were colonies back then) sent us the sample to set our measurments by, the bottle was not sealed properly, and some evaporated, and we did not know it for many years.
Let's talk logic: You carry a yard with you (it's a pace), and a half yard (elbow to biggest extended finger), a quarter yard (open your fingers all the way, it's a span). You carry a mile (it's 1/4 or 1/3 of an hour walking, almost exactly). you carry a cup (just cup your hands). You even carry 10 degrees of arc (it's 5 fingers wide when your arm is extended in front of your eyes). 2 lb. of meat or grain is exactly one day's calorie needs. 1 acre feeds 2 people, and is 70 paces square. 1lb. of meat=8 lb. of fruit=16 lb. of vegetables in calories. You eat 1/4 of 10 lb. of food at a meal. Everything is in 2's and 3's, you can do the arithmetic in your head. Try matching one thing, ANY one thing to your body in Metric. And what's the advantage of being able to calculate in 10's if you can't visualize 10 things accurately without counting them? And try reaching for that calculator, or paper and pencil to move the decimal point, to figure 1/3 of the recipe demanding 225g of molasses when your hands are full of batter. What height person do you measure that pace against - I'm 166cm tall my friend is 195cm tall - our pace is quite different, What size hands - small medium large? - to use a system of measurement that relies on your body leads to confusion and error - for trade engineering science - to communicate to each other you need a common system of measurements that everyone can use and is the same for everyone - that is why metric is used as SI units Systeme International - it is the same for every person no matter where they come from
What's the logic of metric? You try measuring 1/10,000 of the earth's quarter circumference through the Metric committee's home office in Paris to figure out how long a meter is. Then try weighing 1cc of water to get an accurate gram. Remember it must be at sea level (which is changing as the icebergs melt) and standard temperature and pressure. A meter is defined as the distance light travels in 1/299 792 458 of a second in vacuum. It uses a universal constant. The kilogram is measured against the International Prototype Kilogram, you were thinking of an old unit called a Grave
Oh, that's right, the names are all the same, because they are based on the universal languages of Greek and Latin. Greek and LAtin might be universal in europe, but try telling that to African tribesmen, Moslems, Chinese or Pacific Islanders. If your language lacks an r or an l, how do even say meter or liter? Do you know Greek does not have a letter for h? You can write hecto with a reversed apostrophe, but you have to learn the Latin alphabet if you are Greek and want to abbreviate hecto- anything or talk about land in hectares. And milli- and meter are both m. So what do we do with micro-? You try to find the Greek letter mu on your English keyboard. Meter is m milimeter is mm no confusion. u can and is used for mu ie a micrometer is um. English - unfortunatly is the lingua franca of the world at the moment - I am conversing in english with you - my language has no h, k, j, x or z - that does not stop me communicating
America was Metric before the UK, by the way. We had 10mills=1 cent, 10 cents=1 dime, 10 dimes=1 dollar, 10 dollars=1 eagle, 10 eagles= 1 century while you folks were messing with farthings, pence, shillings, pounds, and crowns. But a 10 penny was still worth one quarter, and a "hay-penny" one American cent. OK - I'm not from the UK and this is currency not measurement.
I never heard anyone say milli-inch or kiloyard until your post. Are you sure we are doing that? They are engineering terms.