BROKEN ARCH • DICTIONARY ONE.COM • Definition of Broken arch

... palisaded, and within it the gate of the boulevard. When that was won, and the boulevard taken, men defending it might flee across a drawbridge, over a stream, narrow and deep and swift, into Les Tourelles itself. Here they were safe from them on the side of Orleans, by reason of the broken arch of the bridge. So strong was this tower, that Monseigneur the Duc d'Alencon, visiting it later, said he could have staked his duchy on his skill to hold it for a week at least, with but few men, against all the forces ...

— A Monk of Fife • Andrew Lang