Dear Prof. Einstein,

Those stringers are generally made of round sectioned ash rods, fitting each other through alu or brass sleeves. We assume it's the best solution, but I fear those could lack flexibility on a larger beamed boat.
So what about the square-sectioned alternative ? Those fold in three-sided square-sectioned metal moldings or sleeves, drilled for riveted axles.
But which will be stronger: a 3/4" square log or a 3/4" rod? Or equal?
And which will be the more flexible of the two?
Will a 3/4" x 4/5" thick stringer bend easier on its larger side than a square 3/4" by 3/4"? I've heard that flexibility of a stringer also depends on its shape.

Regards