1 the circle, I believe is 360 due to measuring the movement of the stars. In making a sort of "star dial" the cirlce is related to how long it takes for the stars to do a full revolution. If you are familiar with astrolgy you will note that each sign, denoted by a group of stars, begins at a slightly different time each year, sometimes a different day. this has to do with the wobble of the earth in it's rotation. If you look at charts you will see some that leave this in and you have unequal houses, others have been standardized with 30 degrees per house. This equalizing has to do with mathmaticians at the time messing with nature, 2. The width of the rails does have to do withI think an isosolese( ok, I can't spell) triangle and balance. A certain ratio between the base width and sholder hight of the animal pulling the cart and average height of a man plays into it. Made for the sturdiest, non tipping wagon or chariot. When it was realised that to connect all the railways and the need for a standard, they went back to the wagon standard. 3. as geep says, he is waiting for p5.