"Can you tell me what it is?"
My brother was shaken from his calm at last. He gave an exclamation.
"Yes, I can!" he said. "I know very well. But first, when was this photograph taken?"
With dramatic suddenness, he held out one of Dickson's prints. It was a picture of Mr. Jones' motor, with that gentleman at the wheel and the Doctor sitting on the far side, taken that very morning as they left for London.
"This morning," I said. "That is the Doctor and Mr. Jones going off to town."
"Mr. Jones at the wheel?" my brother asked.
"Yes, that is the fellow."
"Let me get it quite clear. The man, you say, walks like me?"
"Yes."
"Ah!" said my brother again, and his eyes had the look of a bloodhound on a leash. "And now I will proceed to explain to you the use of this pretty thing."