'I been thinking,' said Gustus, on the third day. 'When I'm a man I'm a-going to be a burglar. You has to use your headpiece in that trade, I tell you. So I don't think thinking's swipes, like some blokes do. And I think p'r'aps it don't turn everything big. An' if we could find out what it don't turn big we could see what we wanted to turn big or what it didn't turn big, and then it wouldn't turn anything big except what we wanted it to. See?'
Edward did not see; and I don't suppose you do, either.
So Gustus went on to explain that teacher had told him there were some substances impervious to light, and some to cold, and so on and so forth, and that what they wanted was a substance that should be impervious to the magic effects of the spy-glass.
'So if we get a tanner and set it on a p
