SLIPPERY ROCK — As a loyal listener of National Public Radio, Slippery Rock Mayor Ken Harris has been sending in answers to the network's weekend word puzzles since the time postcards were used instead of the current e-mail.

Harris was chosen to play the puzzle game Sunday with on-air host Liane Hansen and Will Shortz, The New York Times crossword puzzle editor, who runs the contest for Weekend Sunday Edition.

Harris was randomly picked from the hundreds of contestants who correctly answered the question from the previous Sunday show.

He received a call Thursday from NPR, and recorded the show that afternoon. His recording aired on NPR Sunday.

"It's kind of funny, very low pressure, and it's kind of fun and a little silly," Harris said of the puzzle segment. "It's a lighthearted moment in the middle of a broadcast that could be dealing with serious news."

The puzzle Harris answered correctly the week before was a word link challenge that asked listeners to go from the word "carbon" to the word "circuit" with common phrases that began with the letter C. Harris answered by linking carbon to copy, copy to center, center to court, court to case and case to closed to end with closed circuit.

After playing this past Sunday, Harris now waits for his reward.

"There is a prize, and right now they are puzzle books," Harris said. "They asked for my address and they will send me a box of prizes. The thing that is most coveted in this is an NPR lapel pin that the puzzle winners get to wear."

Before starting the recording, Harris talked to an intern at NPR about Slippery Rock and the weather in Western Pennsylvania. When Hansen and Shortz came on the line, the two talked about Hansen's recent vacation to Los Angeles before Harris started the puzzle.

The puzzle Shortz presented to Harris consisted of two word phrases, the first word beginning with "p" and the second beginning with "su."

One question that stumped Harris was an answer for a football star who once was the spokesman for True Value Hardware stores. Hansen helped Harris by giving the correct answer of Pat Summerall.

But when faced with another question about a chemical compound on the periodic table, K2SO4, the former chemistry major answered without missing a beat.

"I hadn't thought about that for 50 some years, but it is a subscript for a chemical formula," Harris said. "I was a chemistry major 50 some years ago and it's weird how the mind works. It's potassium sulfate and it popped into my head as if it were yesterday."

Harris doesn't know why he couldn't answer the Pat Summerall question but quickly answered the chemistry one.

"That was one of the things Liane and I talked about after the recording finished," Harris said. "It was great fun."

While Harris doesn't listen or play the puzzle game every week, he has been listening to NPR at WYSU radio in Youngstown, Ohio, since 1981. The puzzle segment airs every Sunday between 8:30 and 8:45 a.m.

"I sent in a couple postcards and a couple e-mails over a 30-year period," Harris said. "I do think there are people who play every week and it's a fun thing to do."

Harris also said many of his friends and family called him Sunday after listening to the program.

"I did listen to it Sunday and it barely finished when a friend from West Virginia called me who had a party at his house and gathered a bunch of my old neighbors and friends and they had a puzzle party," Harris said. "They passed the phone around and we chatted with old friends."

Harris said he enjoyed the experience.

"It felt comfortable and fun to do," Harris said. "The people at NPR were just amazingly friendly. These were really people able to put you at ease if you were nervous and it was very comfortable."

The show received about 2,000 entries for the question Harris answered to get on the program. He said while he may not enter again, he definitely will keep listening.

"I don't know if I will play again, but it's just fun to work out the puzzle," Harris said.