It is sometimes called Gunter's chain after the man who introduced it. The league is an old international measurement but has different values depending on the country. It was the distance between marker stones placed on roads. The English league is 3 statute miles; the French and Spanish league varies between localities, but is about 2.
The metric league is 4 kilometres. Nautical Measure - The fathom is a nautical and mining measurement based on the space to which a man can extend his arms.
The shackle is used for the measurement of ropes and anchor chains on board ship. The Knot kt is a unit of speed and equals one nautical mile per hour.
It is used in aviation, meterology and at sea. A shackle is a nautical unit of measurement. There are fathoms to the mile. There are 6 feet in a fathom. About Anchor chains for ships are made up of fathom lengths of chain joined by detachable links. The joins are distinctively marked so a ship's officer can estimate at a glance how much chain is out. In the merchant marine, the detachable links are painted red.
At 15 fathoms, the end of the first shot, the two links on either side of the detachable link are painted white, and 1 turn of wire is wound around the stud of the link on either side of the detachable link. At 30 fathoms, the 2 links on either side of the detachable link are painted white, and 2 turns of wire are put on the second stud on either side of detachable link, and so on for the remaining shots.
In the merchant marine, in the command to let go the anchor the amount to be played out is given in shots; in the Navy it is given in fathoms. Log in. Math and Arithmetic.
Length and Distance. Study now. See Answer. Best Answer. Study guides. Algebra 20 cards. A polynomial of degree zero is a constant term. The grouping method of factoring can still be used when only some of the terms share a common factor A True B False.
The sum or difference of p and q is the of the x-term in the trinomial. A number a power of a variable or a product of the two is a monomial while a polynomial is the of monomials. J's study guide 1 card. What is the name of Steve on minecraft's name.
Steel Tip Darts Out Chart 96 cards. Multiplication chart! It does make sense to call north, south, east and west the cardinal points, since those are the main points of the compass, and 'cardinal' means 'of fundamental importance'. For more information about compasses, see this Compass Tutorial. While angles are, of course, not confined to the sea, they follow on from the previous subject. There are degrees in a circle or 'full turn'. This is a useful figure, since it can be divided in many ways, so if you want to divide a round cake into 3, it's degrees, 4 pieces are 90 degrees, 5 pieces are 72 degrees, 6 pieces are 60 degrees, and so on.
One degree is a very small amount, but if you want something smaller, then there are 60 minutes to a degree, and 60 seconds to a minute. So there are 1,, seconds to a circle! My father, who was a gunner in World War II, said that to estimate small numbers of degrees of direction, you stretch out a straight arm, with clenched fist, knuckles upwards.
The distance between the knuckles of the first and second finger was about three degrees, while between the knuckles of the second and third, or third and little finger was about two degrees. My husband who studied astronomy, thinks that a little finger nail is about one degree if you hold your arm out-stretched.
People use different ways to describe a direction. The compass points will only work if you know where North is. For example, on the South coast of England, they mark on the road N,S,E,W because everyone knows where the sea is, and roads tend to run along the coast, or head towards or away from the sea. I notice that a correspondent about paper uses North to mean the top of a piece of paper - obviously because maps are supposed to have North at the top although I've known some that don't - very disconcerting!
But you would never describe North as straight ahead. You can say straight ahead or left or right, or perhaps 'third on the left' if you're going round a roundabout, but this won't help you if you want to give a more precise direction.
A good method is to use a clockface, such as 'two o'clock', or 'half past ten'. This imagines that twelve o'clock is straight ahead. So two o'clock is 60 degrees to the right. Once explained, anyone can use this system, while degrees tend to fluster people who think they are bad at Maths! But it's not quite as simple as that. The Oxford English dictionary said that in a plane, twelve o'clock could mean directly above you, so "Bandits at six o'clock" meant enemy aircraft below you.
Planes work in three dimensions! My father see above gives yet another meaning, as used by an observation post to guide guns firing or describe where a shot had landed. Here, twelve o'clock is north, rather than the direction that you're facing.
Obviously the observation post and the gunners might be facing in different directions, but north stays as north. You use the clock system rather than the points of the compass as everyone understands clocks. While I am talking about direction, it is notorious that the British and a few other countries drive on the left of the road while the rest drive on the right.
The British have a reason for this. We drive on the left, because horses travelled on the left, and the reason for this is that you mount a horse on the left, and you don't want to mount a horse in the middle of the road!
And you mount a horse from the left, because if you are wearing a sword, and if you are right-handed, the sword hangs from the left hip, and if you try to mount a horse from the right, it's liable to get between your legs, which is unpleasant when you sit on the saddle.
Isn't that all logical? I wonder why the rest drive on the right! Jesse Deane-Freeman from Australia has told me this: "I wanted to mention because we drive on the left also another historical reason for driving on the left which was to keep the right hand free to either shake hands or wave with passers by - or to engage in sword or gunplay with a passing enemy.
Apparently this was a defining factor in Napoleon's conversion of captured countries to right hand driving because he was left-handed - I am as well so I understand his reasoning! And this is apparently another historical reason for the English and therefore Australian retention of left hand driving - because we weren't converted by the French!
Now Napoleon being left-handed makes sense it was all obviously the French's fault, as usual. It doesn't explain America, unless they were being deliberately anti-British but drew the line at metric measurements! I'm not so sure about fighting. When knights on horseback jousted, they didn't pass right side to right side as you might expect, even though that side was where their spears were.
They passed left side to left side, as that was where their shields were, and the shields were supposed to protect them. However, pistols would make more sense. If you were passing an enemy on the right and were right-handed, you risked putting a bullet through your horses head.
But cavalry never seemed to use guns. Getting back to angles: In Mathematics, we meet another way of measuring angles - radians. There are 2 pi radians to a circle, where pi is the ratio of the diameter of a circle to its circumference round its edge.
It should have its own symbol, but this might not work on all browsers, so I'm not using it. It looks like a minature Stonehenge. It is a very strange number, approximately 3. This is called an irrational number, and pi is, perhaps, the most famous example. I am tempted to call mathematicians pretty irrational to use a unit where you not only don't get a whole number of them to a complete circle, you don't even get a rational number or fraction!
They would defend themselvese by stating that if you cut a slice of cake with angle of one radian, then its rounded edge is the same length as its straight sides or the radius of the original circle. There are also formulae which are easier to deal with if you use radians rather than degrees.
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