A fisherman from the city was out fishing on a lake in a small boat. He noticed another man in a small boat open his tackle box and take out a mirror.
Being curious, the man rowed over and asked, "What is the mirror for?"
"That's my secret way to catch fish," said the other man. "Shine the mirror on the top of the water. The fish notice the spot of sun on the water above and they swim to the surface. Then I just reach down and net them and pull them into the boat."
"Wow! Does that really work?"
"You bet it does."
"Would you be interested in selling that mirror? I'll give you £30 for it."
"Well, okay."
After the money was transferred, the city fisherman asked, "By the way, how many fish have you caught this week?"