Measuring for confusion
Measuring for confusion
I grew up in the age before calculators and was fortunate that, at school, Wednesday was mental arithmetic day. This was also before metrication and decimal currency. Our grandchildren are baffled by feet and inches but little did they realise that the duodecimal system (12 inches to the foot) had so many easy short cuts. Then they tell me that metric is easy because it so easy to multiply and divide by ten. But, it is so much easier to multiply and divide by 12. The only factors of 10 are one and five, but for 12 there is 1,2,3,4,6. More on this in a moment.
Turn the clock back hundreds or thousands of years and there was no precise standard for measurement. The best that could be invented was the distance from the king's nose to his fingertip (looking left, centre or right I wonder) or the length of five grains of wheat. If the Chinese used rice, would that have been short grain or long grain? So, how did they build the great cathedrals with such precision? No problem because the architect in charge had a stick or piece of metal with two lines on it and said “This is the standard upon which I have designed the building”. Each tradesman would then multiply or divide that standard dimension. For me, the proof that the system worked is to be seen at Trajans column in Rome. It is essentially a stack of stone drums supplied from several different masons yards and yet they fit perfectly. Not only is there a story carved on a spiral on the outside but there is also a spiral staircase inside.
When I am challenged that metric is better, I suggest that we mark off some screw holes at 9” centres. Away we go, 9, 18, 27, 36,45........ Meanwhile my metric friend has started 225, 450, errrr 675, 900? The numbers are awkward and big. Ah, they say, but we have ten digits on each hand. True, but I have 12 joints on the fingers of one hand which is far handier. We you worked in the softwood trade, it was sold by the Petrograd standard of 165 cubic feet. (Actually the volume of 120 boards 12' x 11” x 1½”. This might seem like an awkward number, but it is equal to 23,760 feet of 1” x 1”. Now there were 240 pence in a pound, so if you added 1% to the price in £ per standard, that gave you the price, in pence, of 100 feet of 1” x 1”. And if your wood was 2” x 4”, then multiply that price by 8. Easy peasy, no calculator needed.
If you wanted top know the number of pieces in a pack and the total length of timber therein, we had the Swedish Chain calculation that would give you both, with no calculator, in seconds.
In the world of hardwoods, it is sold by volume of course, but to keep track of it in the timber yard, all you need to know is the surface area. Since all the boards are the same thickness you can multiply by the thickness at the end. So, somebody had to measure each board and calculate its area.
When you go to buy hardwoods, you probably buy FAS Firsts and seconds. There are many lesser grades. The grader looks at the board and imagines it cut into a number of perfectly clear rectangles. He/she adds up the total area of clear wood and compares it with the area of the whole board. If there is 83 and one third or more clear wood, then it is FAS. That is a funny number is it not? Well, no because it is just 11/12ths. Take from this that graders/measurers know their 12 and11 times tables.
When I started work I was given a 3 foot folding boxwood ruler with the Department of Weights and Measures crown stamp. I still have it and several more besides. See photo. One of these even has a slide rule built into it for quick calculations. That same rule is marked off with some kind of ready reckoner and I can't see what it is for. Answers please!
All the stacks of timber were of a single thickness, so all you had to do was add together the area of each board and then multiply by the thickness to get the volume. Well, no you didn't because it was easier than that. If the boards were 1” thick, then just divide by 12. For 1¼” divide by 10, for 1½” divide by 8, for 2” divide by 6, for 2½” divide by 5, for 3” divide by 4 and so on. And life was easy.................then along comes metrication. Try something really easy. Take a board 10 feet long x 9” wide. You can say immediately that its surface area is 7½ square feet. Now make that metric – 3.3metre long x 22.5 cm wide. How is your mental arithmetic now! The numbers are really unfamiliar and awkward.
The Burnikell Ruler
So now let us remember a certain genius, Mr Burnikell who worked for Gliksten Hardwoods, International Timber. He was aware that way back in the early part of the last century, France, Belgium and Holland would supply the UK market in imperial measure but with lengths of 'metric feet' which were one third of a metre. So, he invented the Burnikell ruler. It is a metre long, but divided into three 'metric' feet. The reverse face is divided into 33 and one third (sorry but I can't type thirds on my computer) 'metric inches'. Now metric feet and inches don't exist but no matter because they are familiar round numbers that we can easily multiply together, BUT, to get the surface area you divide by 10, not 12, and that gives you 'metric square feet' which just happen to be precisely one tenth of a square metre. Genius! And so life goes on.........BUT THEN......early 1970s, enter the cheap electronic calculator. This enabled buyers to insist on full, precise, length width and thickness measurement and so the need for mental arithmetic went and so the Burnikell ruler never really earned its place in history.
So, am I an Imperial dinosaur or a modern metric? Well, both, whichever is more convenient. My machines are calibrated metrically, but for handwork I use a bit of both. I could argue about how wasteful the mixture of systems is........ but don't get me going on that!
