When an enormous pumpkin was first sighted atop Cornell University's 173-foot bell tower last October, impaled on a seemingly inaccessible lightning rod, school officials said they would need to hire a crane or erect scaffolding to remove it.

But they decided it was not worth that much trouble and expense to take a pumpkin from the lofty perch. Instead, the university put up a bright orange fence around the tower, posted signs that warned passers-by to beware of a falling pumpkin, estimated to weigh 60 pounds if real, and decided to let it just rot away.Four months later, the mysterious gourd remains intact, and no one knows how it got there or who did it. Many professors and students debate whether it is indeed a real pumpkin. Some have suggested that it is chemically treated, or that it is made of clay, plastic or papier-mache; others say it must be real because it is slumping as a real pumpkin would under similar conditions.

Either way, Cornell will get to the bottom of one of the mysteries. Next month, workers are scheduled to use a large crane and scaffolding, which will be at the bell tower to replace a column in the belfry, to reach the pumpkin and take a sample. Then they will leave the pumpkin where it sits atop the tower and let nature take its course.

Some students have said that the university is going ahead with the tower's first restoration in decades only to investigate the pumpkin. But school officials insist that the project is not a cover for some pumpkin detective work.

"It's remarkable," Hal Craft, Cornell's vice president of facilities and campus services, said of the students' speculation. "But believe me, it's a coincidence. We've been talking about this project for two years."

The university's pumpkin sample will be used to find a winner in a contest, started at the suggestion of the university's provost, Don Randel, in which undergraduates are asked to determine the true composition of the pumpkin.

Participants can work alone or in groups, and have to submit their entries by March 13. Otherwise, the only rule is that contestants stay on the ground while studying the pumpkin, which is perched above the bell tower's steeply pitched metal roof. While that bars the use of a blimp, helicopter or rappelling equipment to reach the top of the tower, school officials said that radar and radio-controlled devices are fair game.

"I can think of a dozen different ways to solve this problem," said Mary Sansalone, a professor of civil and environmental engineering at Cornell who helped organize the contest. "But I would rather have students come up with the ideas themselves."

Graduate students are disqualified because they often have access to more sophisticated equipment and technology than undergraduates.