My paws trotted onto the low bookshelf where a heavy vintage rubber date stamp was resting beside an ink pad. Chuckle. Around its metal frame were ribbed rubber bands loaded with tiny raised numbers. I scrambled onto an overturned leather bookmark, wrapped both paws around the serrated wheel, and gave it an ambitious turn. Squeak-click! The rubber track rolled forward, lining up a sharp '03' right in the center frame. I pressed down with all my weight on the black wooden knob. Thump! A crisp black ring landed neatly on a blank index card, stamping my official flight departure clearance for the morning.