“Gilling is our head mechanic. You can question him about it. He's an intelligent man.”

In a few minutes the mechanic appeared at the door.

“You wanted me, sir?” he asked.

Markfield introduced the Inspector with a gesture, and Flamborough put his questions.

“You've seen this thing before?”

The mechanic came forward to the table and examined the holder carefully.

“Yes, sir. I made it myself.”

“You're quite sure of that?”

“No mistake about it. I know my own work.”

“Tell us what you know about it,” the Inspector demanded.