"Oh, very well," said van Hoek, and ambled round to the butt of the Haubitz. He sighted down the barrel, then changed focus to the target. "Yes. They moved their keg. But not as far as they ought to’ve." He picked up a stone and used it as a mallet to whack the quoin under the weapon’s butt, depressing its muzzle slightly. "Do you think we need to allow for the rotation of the Earth?"