They remained in their position for a considerable time, when Jim Dennis assumed a listening attitude. His solitary life had caused him to be quick at distinguishing sounds.
'What's up, Jim?' asked the constable.
Jim Dennis held up his hand to ensure silence.
Doonan watched his face, and saw his expression change to one of triumph.
'By the Lord, we have 'em now,' he said. 'Listen! Can you hear that noise?'
Doonan was all attention.
'It's a humming kind of sound. I have heard it before.'
'You have. It is blacks on the march, and they are coming here. If it's King Charlie and his tribe we will catch these scoundrels like rabbits in a net. Come with me, we will ride to meet them.'