"I noticed an extraordinary change in Williams's reports, both in the handwriting and expression. Now I understand it. You work the same stall as Haden, do you not?"
"Yes, sir, but not the same shift; he had a mate he has worked with ever since my father was killed, so I work the other shift with Harvey."
"Now let us look at the plans of the pit," Mr. Hardinge said.
The two inspectors bent over the table and examined the plans, asking a question of Mr. Brook now and then. Jack had turned to leave when his employer ceased to speak to him, but Mr. Brook made a motion to him to stay. "What is the size of your furnace, Mr. Brook?" asked Mr. Hardinge.
"It's an eight-foot furnace," Mr. Brook replied.
"Do you know how many thousand cubic feet of air a minute you pass?"
Mr. Brook shook his head: he left the management of the mine entirely in the hands of his manager.
Mr. Hardinge had happened to look at Jack as he spoke; and the latter, thinking the question was addressed to him, answered:
"About eight thousand feet a minute, sir."
"How do you know?" Mr. Hardinge asked.