The particular chain that went through Jack's collar-hasp had a circular loop – a single oversized link – welded to one end. The chain had been passed around the stone pillar and its narrow end threaded through this loop, then through Jack's collar, and finally one of the duc's smiths had heated up the chain-end in the stable's built-in forge, and hammered an old worn-out horseshoe onto it, so it could not be withdrawn. Typical French extravagance! But the duc had an infinite fund of slaves and servants, so it cost him nothing, and there was no way for Jack to get it off.