It sounds as if you're rotating one finger around the other? The idea is to use two fingers together (like one big finger) to do a pan in a circular motion.
In all my messing around it did not occur to me to try that. Thanks! Solution blinders in action! I suppose a little animation would have gone a long way towards clearing that up initially.
Even doing it correctly, I still feel it's a little too slow, and still relatively easy to flub it into closing the book. I applaud the idea, though.