Hours after Encyclopaedia Britannica announced its free Web content, yesterday, its site went down. Some visitors to Britannica.com reported they couldn't reach the site at all, while others reached the site - but found it wouldn't accept searches. It's not known how many users were turned away. The company is calling the problem a "temporary slowdown".

A Britannica.com spokesman said: "Our servers have been over-run with traffic."

Today, visitors to the site will see a letter from CEO Don Yannias, apologizing for the outage. "In many ways, we have truly been victims of our own success. We knew that the site would attract a significant number of users in its first days of operation, but we had no idea that this volume of traffic would be achieved so quickly," Yannias said in the letter. He pledged to have the outage resolved "shortly".

Encyclopaedia Britannica began offering the free Web content yesterday. Until now, Britannica.com charged a $5 monthly subscription fee, and the site contained only encyclopedia content. The new site plans to feature encyclopedia text, plus news articles from 80 newspapers and magazines, and links to related Web sites.