Masons, when they start upon a building, Are careful to test out the scaffolding;

Make sure that planks won’t slip at busy points, Secure all ladders, tighten bolted joints.

And yet all this comes down when the job’s done

Showing off walls of sure and solid stone.

So if, my dear, there sometimes seem to be Old bridges breaking between you and me

Never fear. We may let the scaffolds fall Confident that we have built our wall.

“Scaffolding” from Opened Ground: Selected Poems 1966-1996 by Seamus Heaney.