Stately and welcoming, fronted by a glass-enclosed portico and topped by a widow's walk, the Victorian landmark known for generations as the Mount Holly Library ceased, on Friday, to be.

So, why was everybody inside smiling, clapping, and shaking hands?

Because this architectural gem on High Street, whose survival had seemed precarious for years, had just come into the possession and protection of Burlington County, which will turn it into a history museum and "lyceum."

"This is a pretty historic event in a pretty historic building," Freeholder Director Joseph Donnelly told the 30 people perched on Windsor chairs in the ground-floor meeting room.

And though plaster busts of famous scribblers such as Mark Twain and Edgar Allan Poe still gazed down from the bookshelves and mantels, this was not the Mount Holly Library any more.

The 1830 building, which the county acquired from the township for $10, will henceforth be known as the Burlington County Lyceum of History and Natural Science, returning to it the official name given it by an act of the state Legislature in 1860.

Popular in the Victorian age, lyceums were centers of study and public education that often included exhibit space and lecture halls.

The new lyceum aspires to be all of that while retaining some of its former role as the local library. It will keep its current hours, and the public will still have access to its computers and can order, read, and return books there.

"Residents who return on Monday will find that not a lot has changed," Freeholder Leah Arter said.

Soon, however, a newly assembled transition team of historians and librarians will begin to study how the building, which sits on two landscaped acres, can be modified as a space for research, displays, and lectures.

Former head librarian Michael Eck, who became a county employee Friday, will stay on as the lyceum's director. He and his staff of two part-time librarians are already sorting out which books, maps, and items of historic value should stay and which might belong at Burlington County's main library in Westampton, two miles away.

The library, or lyceum, moved into the current building, known as Langstaff Mansion, in 1957. It traces its origin to a private library association club created in 1765 by a charter from England's King George III and still has more than 100 of its original volumes.

Eck described the transition to county ownership as a "dream come true," because the financially strapped township had in recent years been scaling back its financial support of the facility, which needs about $100,000 a year for salaries, utilities, insurance, and upkeep.

"See that corner?" he asked, pointing at water marks on two walls of the meeting room. "That's where the roof started to go."

In the spring, however, Mount Holly Deputy Mayor Rich DiFolco approached the freeholder board about the building's plight, and, after some study, the board agreed to take it over.

"It was quite an uncomplicated real estate transaction," Donnelly said in his remarks Friday, adding that there was no scarcity of ideas for the space. He predicted it would become a destination for school groups, the county's 26 historical societies, and the public, and would anchor the township's historic district.

He was followed by DiFolco, who thanked the freeholder board for "moving in the right direction," and by Alicia McShulkis, president of the board of trustees, who predicted "changes and growing pains," before handing Donnelly a set of brass keys to the building.

"Look at that," exclaimed Donnelly, who appeared surprised. "We got the keys."