Three engineers got on a crowded lunchtime bus. They somehow worked their way to the middle of the bus where they found three girls willing to exchange their seats for a place on the guys' laps. After they got settled and had ridden that way for a while, the first girl suddenly asked the gentleman under her whether he might be an electrical engineer.

Surprised, he replied, "Yes, I am! How did you know?"

"Easy," she said. "I'm getting shocked by your soldering iron."

Just a few minutes later, the second girl asked her guy, "Are you a mechanical engineer?"

He said, "Why, yes, ma'am. How did you know that?"

"Simple," she said, "Your piston is scraping my cylinder."

Shortly thereafter, the third girl turned to her fellow and asked, "Are you a civil engineer?"

"I certainly am," he answered. "How could you have known that?"

"Well," she said, "I figured it out as soon as your dam burst and flooded my village."