As post-graduate degrees go, Lorna Howley's requires an intimate knowledge of the arcane and mundane.

How many people, after all, have to know Ben Franklin's itinerary on the day he arrived in Philadelphia and the closest place to get an authentic Philly cheesesteak?

It's all part of the learning curve for about 80 actors who graduated yesterday from the "Benstitute," the three-week course run by Historic Philadelphia Inc.

"When I first got this job, I had no idea what it was going to be like," said Howley, 46, of West Philadelphia, an actor-director for 20 years who moved here from Atlanta four years ago.

Howley said she found the work so enriching that she wanted to return for a second year.

At the graduation, some dressed in colonial costume as historic characters and others as storytellers in the trademark mint-green polo shirts emblazoned with "Once Upon a Nation." They assembled in front of the historic fountain in Franklin Square, where they were greeted by a reincarnated Benjamin Franklin in the form of Ralph Archbold.

With three hearty "huzzahs," Franklin welcomed the grads to what he called "the most beautiful park in America's most historic city."

"This is the city that takes history seriously," he added.

That's a much-discussed topic. Spurred by reports of independent tour guides winging it when it came to Philadelphia history, Mayor Nutter last week signed a bill requiring guides to pass a test of their knowledge of the "geography, history, historic sites, historic structures, historic objects and other places of interest in the Center City Tourist Area."

That was already the idea behind the four-year-old Benstitute: to teach guides and performers in the area around Independence Mall how to help visitors have fun, find their way around, and learn something historically accurate in the process.

The grads begin work Saturday, the beginning of the Memorial Day weekend and the official start of Old City's tourist season. This year, for the first time, a contingent of Benstitute grads will also staff four spots at Valley Forge National Historical Park.

Meryl Levitz, president of the Greater Philadelphia Marketing Corp. and a moving force behind the Benstitute, told the grads the program was designed to give visitors something unique.

"They're looking for the real deal. They're not looking for something they can find everywhere else," Levitz said.

Nevertheless, she added, historic accuracy is important: "We want to make sure what we say happened here really happened here."

The Benstitute is just part of a program to make historic Old City more than just a tour-bus stop to see Independence Hall and the Liberty Bell.

Instead of leading boring tours of old buildings, Historic Philadelphia Inc.'s "Once Upon A Nation" performers circulate around the mall.

Some are in character portraying figures such as Franklin, John Adams and Thomas Jefferson who talk with visitors at historic sites associated with them.

Others, such as Howley, are storytellers, who stake out one of 13 semicircular benches and wait for visitors, often children, to stop by and rest.

All the grads are professional actors - they earn $13 to $16 an hour - and auditioned before they were hired, said Sandy Mackenzie Lloyd, the Benstitute's director and a trained historian and museum curator.

About a third are newcomers, such as Kaylah Fitzgerald, 19, who moved to Philadelphia from South Jersey.

Fitzgerald said her storytelling would focus on young children in Franklin Square. Some of them undoubtedly will be brought there by parents to take advantage of the mini-amusement park and playground installed by Historic Philadelphia Inc. during its $6.5 million renovation of Franklin Square, which was completed in 2006.

But for Fitzgerald it's also another paid professional credit to add to the resume of an aspiring television and film actor.

For the last three weeks, the actors have learned history, got refreshers in acting and voice, and received training in storytelling from Charlotte Blake Alston, the Philadelphia-based storyteller, narrator and singer. They also were briefed on public security and how to deal with urban encounters with homeless people, panhandlers and reporters.

In addition, they're expected to know locations of the nearest restroom, restaurant, or spot to sit and rest.

It's a service Ben Franklin himself would have appreciated had it existed when he arrived in Philadelphia in 1723, a 17-year-old Boston runaway looking to make it on his own.

"The Benstitute trains these people, and every year they do a great job helping to develop a definite flavor for visitors," said Franklin/Archbold. "People come here and get to talk to someone from the 17th century, not just seeing the buildings."