circle out of anything

Q: In SF p.66, Harry draws the circle to contain Toot, memorizes it’s exact location, then covers it with leaves and twigs to hide it from view. Toot eats, the circle closes – everything works. However, on p.175 (when he and Susan are being attacked by the demon), Harry goes nuts ensuring that every scrap of paper is clear from the circle in his lab (the copper circle he installed in the floor – he should remember where it is… ) prior to activating it. I’ve gotten the impression that a circle’s perimeter needs to be clear before activating it. Is this an inconsistancy, or am I missing something?
A: Something to do with the environment here, too.  You can’t have any foreign objects interrupt the circle.  But since the circle was being made out of earth and twigs and leaves, it isn’t going to be disrupted by earth and twigs and leaves.  It still could have been /broken/ by one of them, if any of them had actually marred the circle drawn in the earth, so that it wasn’t a complete shape any more (not just fallen over it).  For that matter, if Toot had scuffed his foot through the circle on accident on the way in, that could have blown the trap, too.
Different situation with a big copper circle in a smooth concrete floor.  I mean, I suppose Harry could have made a circle out of, I dunno, dirty laundry or something, and other dirty laundry laying across it could obscure it without breaking it.  But then if the wrong sock gets shifted, pift, no circle any more.  Much safer to go with the big metal circle in the floor that you know isn’t going to be broken, and just take extra pains to make sure nothing falls across it.
Jim

JoeC (http://www.jimbutcheronline.com/bb/index.php?action=profile;u=2547)  February 14, 2007