A massive ship's engine broke down, paralyzing the vessel and costing the owners thousands of dollars every day. The ship's crew and several top mechanical experts tried for days to fix it, but no one could figure out the problem.
In desperation, the captain called in an old mechanic who had been repairing ships for decades. The old man arrived carrying only a small bag of tools. He walked slowly around the massive engine room, quietly listening to the machinery as they turned it on and off. He looked closely at the complex maze of pipes, feeling them with his hands.
After a few minutes, the old man reached into his bag, pulled out a small hammer, and tapped a specific valve just once.
Immediately, the engine rattled to life and began running perfectly. The captain and the crew were amazed.