Marvin Gelfand, who is legally blind, leads tours of New York for Walk of the Town (212-222-5343).

Q: How much sight do you have?

A: I've been certifiably legally blind since 1984. I can make out some things but it's very distorted, depends on the weather and the shifts in light. Put it this way: In the duel scene from "Romeo and Juliet," Tybalt's lying there mortally wounded and somebody asks him what's the wound like and he replies, " 'Tis not as high as the church spire or as wide as the barn door, but 'twill do."

Q: Describe the challenges you face when leading a tour.

A: There are none. I mean, I've fallen on tours, banged myself and led people into traffic--which is very embarrassing. Imagine leading 50 people into Park Avenue traffic. Or I trip over something. But I just say "ouch" and move on. Fortunately, most of the things I describe are rather large and move slowly, if at all. Sometimes friends come along or I grab somebody on the tour and say, "Look, do you mind helping? I'm a little light-sensitive today." I've never been into talking about the minutiae of architectural detail anyway. I'm interested in social history--the city's blood, guts, people--and politics, which is, of course, behind everything.

Q: Do tour guides find their work boring after a while?

A: Some people can become mechanical. Did I ever do it enough to worry about that? No. I've always loved getting up for a tour, even a standard bus tour.

Q: You began guiding in 1980. How has the city changed?

A: I've always been an eavesdropper, and one of the great things you'd eavesdrop on would be the art of seduction. But now, all you hear is young people discussing their 401K plans.

Q: What do you miss looking at?

A: Pretty girls.

Q: What else?

A: The view from mid-span of the Brooklyn Bridge on a clear autumn day, just looking at the Statue of Liberty and the Brooklyn Navy Yards and the whole sweep of it. The Brooklyn Bridge fascinates me the more I learn about it. It's a monument to everything great about the city. The Roebling family--they designed and supervised the bridge--were immigrants. The old man came because he thought Europe was dead. And he came here and built bridges that no one had ever attempted before. It's not just a great engineering feat, it's a monument to what they thought freedom was about.

Q: Reveal a few things about New York City that would surprise most visitors.

A: Few realize the extraordinary religiosity of the city: Manhattan alone has over 100 religious denominations and sects--not counting storefront churches. Then there's the charitableness of New Yorkers. Harried and worried and aggrieved as they feel, most New Yorkers are very philanthropic. Sometimes they even help you when they haven't been asked, which can be intrusive. I got grabbed by three young women today--why didn't that happen when I really needed them?

Q: How do you handle know-it-all clients?

A: If someone gets angry at me for not knowing something, most of the time I'll say, "You got me there. I'm glad you think I know everything, but I don't." I must admit that I get performer's nerves sometimes. My friends say, "Marvin, don't worry, just remember you know 50 times more than the people on the tour."

Q: Are tour guides competitive? When they run into each other, do they flaunt their knowledge of the city?

A: I belong to a group that's met once a month for years. To distinguish us from mere tour guides we call ourselves "urban historians." A lot of those dinners can descend into backbiting. There's a lot of "Can you top this?"

Q: If you could transport yourself around New York City with a snap of your fingers, where would you go in a day?

A: Ellis Island would be indispensable. The essence of the city is now--and, God willing, will remain--a haven for the oppressed and a magnet for the ambitious. The Empire State Building, because of the dreams it represents, would be next. . . . You'd have to hit East Broadway on the Lower East Side, because it was the center of the largest Jewish city that had ever been. Then I'd go to Prospect Park in Brooklyn, which designer Frederick Law Olmsted held to be superior to his own Central Park. Finally, the Cathedral Church of St. John the Divine, because of its grandeur, and the deep ecumenism that the structure and chapels symbolize.

Q: Where do you eat after this quintessential New York tour?

A: Barney Greengrass, "The Sturgeon King," on 86th Street and Amsterdam Avenue. Every time I go in there I hear a combination of young matrons in 12-step programs at the church next door, editors talking to their writers, horse players and ballet dancers. I just love the kind of place where horse players can be sitting next to a guy touting an opera he wrote based on "Viva Zapata!"

Q: How do you warn clients that you have a disability?

A: To paraphrase Bette Davis in "All About Eve," "Hold on, folks, it's going to be a bumpy ride."