Q: I don't always have a rope that's long enough. Is there
a way to securely, but temporarily, tie together short lengths of rope?
—William Wildman, Marlton, N.J.
A: Knots that join ropes together are called bends. My favorite one is a sheet bend, which is easy to tie and won't slip. Unlike the commonly used square knot, sheet bends are especially handy for joining ropes of different diameters, and they're easy to untie after being under a lot of tension.