Walker had the shyness of his nationality in the exhibition of enthusiasm, and he could only express his admiration for the commander of the party in terms of slang.

'He was, my son,' answered Adamson, drily. 'My own impression is, he thought we were done for.'

'What makes you think that?'

'Well, you see, I know him pretty well. When things are going smoothly and everything's flourishing, he's apt to be a bit irritable. He keeps rather to himself, and he doesn't say much unless you do something he don't approve of.'

'And then, by Jove, he comes down on you like a thousand of bricks,' Walker agreed heartily. He remembered observations which Alec on more than one occasion had made to recall him to a sense of his great insignificance. 'It's not for nothing the natives call him Thunder and Lightning.'

'But when things look black, his spirits go up like one o'clock,' proceeded the doctor. 'And the worse they are the more cheerful he is.'

'I know. When you're starving with hunger, dead tired and soaked to the skin, and wish you could just lie down and die, MacKenzie simply bubbles over with good humour. It's a hateful characteristic. When I'm in a bad temper, I much prefer everyone else to be in a bad temper, too.'

'These last three days he's been positively hilarious. Yesterday he was cracking jokes with the natives.'

'Scotch jokes,' said Walker. 'I daresay they sound funny in an African dialect.'

'I've never seen him more cheerful,' continued the other, sturdily ignoring the gibe. 'By the Lord Harry, said I to myself, the chief thinks we're in a devil of a bad way.'