During all this time the Professor went on calmly and persistently mineralogising. 'Wonderful character!' Charles said to me. 'He works out his parts so well! Could anything exceed the picture he gives one of scientific ardour?' And, indeed, he was at it, morning, noon, and night. 'Sooner or later,' Charles observed, 'something practical must come of it.'
Twice, meanwhile, little episodes occurred which are well worth notice. One day I was out with the Professor on the Long Mountain, watching him hammer at the rocks, and a little bored by his performance, when, to pass the time, I asked him what a particular small water-worn stone was. He looked at it and smiled. 'If there were a little more mica in it,' he said, 'it would be the characteristic gneiss of ice-borne boulders, hereabouts. But there isn't quite enough.' And he gazed at it curiously.
'Indeed,' I answered, 'it doesn't come up to sample, doesn't it?'
He gave me a meaning look. 'Ten per cent,' he murmured in a slow, strange voice; 'ten per cent is more usual.'
I trembled violently. Was he bent, then, upon ruining me? 'If you betray me———' I cried, and broke off.
'I beg your pardon,' he said. He was all pure innocence.
I reflected on what Charles had said about taking nothing for granted, and held my tongue prudently.
