We may never know what moved an arsonist to set the pressbox at Soldiers Field on fire one day last spring. Maybe he didn't like what journalists were saying about the Harvard football team. Maybe he was just nuts.

The suspect, an 18-year-old Arlington man, has since (or so it is rumored) been whisked back to the Navy, from which he was AWOL, the debris atop the granite stadium has been cleared, and a brand new press box--one that will never burn down--is nearly ready to start off the 1981 season.

The new press box looks a lot nicer than the old wooden cne built back in 1935, but some significant questions have Harvard Athletic officials wondering whether the new box will offer a real improvement.

For one thing, the new box, scheduled to be rcady eight days before the football team's home opener Sept. 24, will have only 130 seats--90 less than the old one.

The reduced size is the result of a tight $400,000 budget, Joe Bertagna, director of sports information, said last week.

But Bertagna said that 30-40 of the seats in the old pressbox were obstructed view and hence were rarely used. He added that for most games he does not predict any problems in seating.

For big games, such as next year's home Yale Game, however, problems may arise. "That game attracts lot of journalists from all over the country, who come as much for the spectacle as the game itself," Bertagna said.

The first to lose their pressbox passes, Bertagna said, will be "the VIPs and athletic department people--having them in the box was a luxury we could afford before, but may no longer be able to for certain games in the future."

The new box, unlike the old one, is enclosed with glass. This may have both advantages and disadvantages. While the glass will protect journalists from cold winds during the latter months of the season, the box may be stifling hot during September and early October. Only a portion of the windows can be opened, and, because of the limited budget, no cooling or ventilation systems have been installed.

Noise may prove another negative result of the closed windows, but Bertagna said that windows directly in front of those who will be talking, such as tv and radio reporters, can be opened to lessen the noise level.

In general, Bertagna said he and other athletic department officials are happy with the new box. "Considering the budget, I'd say that both the architect and the contractor have done a great job."

There is one unquestionable advantage the enclosed pressbox has over the old one, Bertagna said. Pigeons. "They used to strafe the place to a tune of about $5000 a year in cleanup."