Graham Walker doesn't drone. As he gave a tour of Victorian Back Bay in Boston this month, he varied his cadence and punctuated his points with gestures. Speaking not from a script but from memory, he peppered his descriptions with short quotations from historical and architectural experts, along with observations of his own.
Standing with his back to the Boston Public Library, for instance, he noted the 13 large windows with Romanesque arches that face Trinity Church.
''I like to think of this as 13 nuns in gray habits, all standing quietly -- and they're saying, 'Shhh, we're reading here,' " Walker told his listeners.
Walker, who lives in Lincoln, is one of about 200 volunteer tour guides with Boston by Foot, a nonprofit organization in its 29th year of offering walking tours of Boston. Like Walker, most guides do not live in Boston. For them, the city isn't home, technically, but it is a passion.
''Definitely, living in the suburbs is something I never would have considered 20 years ago," said tour guide Eleanor Rosellini, a children's author and Needham resident who lived on Beacon Hill and then in Dorchester during the late 1970s and 1980s. ''I think, for me, it's especially important to keep a connection with the city."
Boston by Foot is the creation of Lincoln resident Polly Flansburgh, who got the idea in 1976 from a woman who gave similar tours in Chicago. Hard as it is to imagine today -- with Duck Boats and trolleys and parking spots set aside for tour buses -- there were few organized tours of Boston at the time. Flansburgh developed a tour-guide course based on lectures from historians, books on Boston lore and architecture, and actual tours.
Today the organization offers regularly scheduled 90-minute tours, May through October, of Beacon Hill, the North End, Victorian Back Bay, literary landmarks, Boston Underground, and the Heart of the Freedom Trail, along with a Freedom Trail tour designed for children. There also are specialized tours-of-the-month developed by guides. About 10,000 people take the tours each year, most of which cost about $10. Revenues cover expenses, which run about $100,000 a year and include advertising and printing promotional materials.
The training is rigorous. Guides-in-training attend five-hour sessions on five consecutive Saturdays during the spring. The sessions include a two-hour lecture by a specialists on some facet of Boston's history and buildings, followed by small discussion groups and then a 90-minute training tour. Students must complete four papers during the course, which culminates with a two-part final exam: a written test featuring slides of buildings, followed by a tour test, during which each student is picked to give a short presentation from memory on a particular building.
And volunteering costs money. Guides-in-training pay $95 for the course, not including materials. Once they pass, they're not done. To keep their standing, each guide must give at least six tours a year. The training, while hard, ensures a certain standard of knowledge.
Rob Radloff, chairman of the Boston Foundation for Architecture, a nonprofit organization that supports Boston by Foot with grants, said the guides provide valuable information about the city's buildings.
''It's a well-thought-through explanation of the architecture, but in understandable layman's terms," Radloff said. ''They really spend time to get the message right."
Research leads to all sorts of startling discoveries, like the reason Beacon Hill has so many town houses. Terri Evans, a Natick resident who is in her second year of giving tours for Boston by Foot, said builders during the early 1800s originally planned to construct single-family homes there but turned to town houses during an economic downturn because they were cheaper. Learning about Boston's buildings helps unlock much of its history and character, she said.
''The architecture helps you explain the social history of a community," Evans said. ''It tells you a lot about how a community sees itself, how the architect sees the community, and how prosperous the community is."
While the course requires a fair amount of reading, many veteran tour guides do far more on their own. Rosellini, for instance, who gives tours of Beacon Hill, Victorian Back Bay, and literary landmarks, sees her tours as constant study projects.
''I'll read two novels by William Dean Howells because his house is on the tour," Rosellini said. ''It might get me only two sentences on the tour, but I like it. A lot of it is just for myself."
Feeling connected to the Hub is a major draw for guides and organizers.
Flansburgh, 73, the founder and president, has never lived in Boston. She and her husband, architect Earl Flansburgh, who gives the organization space in his North End office, have lived in Lincoln since 1963.
''I love having both worlds," she said of her many trips between city and suburb, comparing Boston's art, people, and diversity with Lincoln's woods and sense of community.
Most guides have war stories, such as giving a tour in wintry weather, which occasionally persists even through spring. (Most tours run rain or shine.)
There are the John Kerry sightings in Louisburg Square, when whole groups of people desert the tour guide to gawk.
Then there was the time Rosellini was giving a tour on Beacon Hill and encountered a passerby who seemed dignified, yet underdressed.
''He looked like a Boston Brahmin somehow, but he was wearing this lovely white bathrobe down Beacon Street."