Answer:
It's got twists and turns, but has no curves. Twist it to fix it, turn it to ruin it. What is it?
If a man carried my burden, he would break his back. I am not rich, but leave silver in my track.
What points the way without a hand. It floats on water but exists on land?
A shimmering field that reaches far. Yet it has no tracks, And is crossed without paths.
When it comes in, From sea to shore, Twenty paces you'll see, No less, no more.
You use it between your head and your toes, the more it works the thinner it grows.