“It's a small shoe,” Wendover pursued, without answering the criticism.

“Size 3½ or thereabouts,” Armadale amended, glancing up from his work. “I shouldn't make it bigger than a 3½, and it might be even smaller.”

Wendover accepted the rectification, and continued.

“The step's not a long one either. That looks like a rather small girl with a neat foot, doesn't it?”

Sir Clinton nodded.

“Looks like it. Have you a tape-measure, inspector? We ought to make a note of the length of the pace, I think. It might turn out useful. One never knows.”

The inspector fished a tape-measure from his pocket; and, with the help of Wendover, Sir Clinton made measurements of various distances.

“Just twenty-four inches from one right toe-mark to the next,” he announced. “And it seems a very regular walk. Now if you're ready, inspector, we'll go on to the next trail. It's the single one, so it's probably the murdered man's.”

They moved round the rock a little. The inspector's face lighted up at the sight of the footprints.

“Rubber soles, sir; and a fairly well-marked set of screws to check anything with. If they do belong to the murdered man, we'll have no trouble in identifying them.”