We wondered what the fuss was about as we congregated on a nondescript downtown side-street, 20 or so architectural buffs and NYC civic nerds who came expecting a special exploratory treat. We were gazing up at some standard city-owned office building—346 Broadway between Leonard Street and Catherine Lane—about a dozen stories tall, built some time in the last century and showing it, with the requisite architectural flourishes and crumbling detailed exterior. But we weren’t scheduled for some downtown boredom tour; both the building and the event’s coordinators promised secrets that weren’t visible from the sidewalk.

They also promised free coffee and pastries, and when those didn’t materialize—my stomach rumbling, demanding sustenance—I plodded across the street towards a deli. On a whim, I turned around and looked up. Sticking out against the sky, just visible from the western sidewalk above the ugly wrap-around blue plywood scaffolding and steel pipe-work, there she was: an enormously anachronistic four-sided clock tower. It said 9:45. I cross-checked with my Casio calculator-watch. Time to climb up.

The Lower Manhattan Cultural Council is a City-funded non-profit, located on Maiden Lane, that produces public and gallery-based art spectacles and other idiosyncratic events. The Council sponsors the yearly Art Parade that marches through the Financial District each June, as well as site-specific dance performances under the title Sitelines. The group likes to engage forgotten and/or under-utilized civic spaces of Lower Manhattan and twist the presentation—i.e., a modern dance piece on the steps of the Federal Hall National Monument.

The Council’s current lecture series is held inside various landmarked civic buildings scattered downtown—once a month, approximately 30 lucky New Yorkers gather for a tour and lecture. This month we were offered access to and information on the largest and last manually wound and working clock tower left in the city.

The building that serves as pedestal to the clock tower was built in 1894, an Italian Renaissance Revival by Stephen Hatch that served as corporate headquarters for the New York Life Insurance Company. In the middle of construction Hatch passed away, and the completion of the building was overseen by the reputable McKim, Mead and White. It has all the attractions of late-Gilded Age New York: a sweeping 13-story marble staircase, a double-height General Office entrance, and an apex crowned with an additional half-floor and a perch in the sky—the clock tower. Unsubstantiated rumor had it that White, an architect known for seeking a good time in the best of places, intended the top half-floor to double as a private social club for him and any number of his underage lady friends.

New York Life moved up to Madison Square Park in 1927, and countless other tenants passed through its halls before the building was purchased by the city in 1968 as part of grandiose plans for an extended civic center that would have occupied much of today’s Tribeca. Luckily, the plans were never realized, or Robert DeNiro would be out of a home.

In 1987, the Landmarks Preservation Commission granted both the interior and exterior of the Clock Tower building landmark status, and the New York State and National Register of Historic Places followed suit. Although this led to various interior and exterior cleanings and renovations, the building still lacks the proper funding to shirk off its dusty jacket; it gives the impression of a roughed, uncut, and dirty diamond amongst the terrifically ugly modernist black coal complexes of Lower Manhattan—just look at the Jacob Javits Federal Building next door in Foley Square. The building is currently occupied by New York Criminal Court, and the top floor hosts P.S. 1’s 24-hour online Art Radio.

Once we were brushed from the sidewalk and through the security detail that is now standard practice for all City buildings, we hustled on and off a few tiny elevators and up a staircase to the 13^th floor. From there, an additional wrought iron, corkspiral staircase led to the ever-promised clock tower. After a history lesson over doughnuts and coffee, which finally appeared in the meeting room where we were gathered, our group of 30 split in half and the first group ascended the DNA strand of steps, up into the lofty aerie of the city’s last manually functioning clock.

Built and installed specially for the Clock Tower Building in 1897 by the E Howard Clock Company of Boston, New York and Chicago, it retains the distinction of still operating on all its original parts, unlike all other clock towers in the city, which have been electrically updated. Two of the city’s most famous clock towers—the Jefferson Market Courthouse in Greenwich Village and the Metropolitan Life Insurance Tower in Madison Square—are electrically run, from the cogs and gears to the pre-recorded, digitally enhanced chiming of the bells.

But not the Clock Tower at 346 Broadway; it runs by weights: one 1,000 lb. weight operates the time-keeping portions of the clock, and two other 800 lb. weights enable the 70-pound hammer to strike the bell on the hour, every hour. The bell, clocking in at 5,000 lbs., is twice the size of the Liberty Bell. The room—cogs, gears, cranks, chains, mallets, hammers, and 4-sided frosted-window clock faces with 12-foot diameters—looks like a steam engine compressed into a really small Manhattan apartment.

If it weren’t for two municipal employees, Mr. Marvin Schneider of Brooklyn and Mr. Eric Reiner of Spring Valley, the clock wouldn’t be working at all. These proud citizens spent hundreds of hours on their lunch breaks and over weekends, on and off for a year, up in the shafts, renovating, rebuilding and refurbishing the clock to working condition in 1979. Prior to that, the clock hadn’t operated for at least 20 years, and the exterior lights hadn’t lit for more than thirty. Marvin is the City’s official Clock Master, and has been for almost 30 years. A small, bespectacled, excitable man with a smoky New York voice—essentially everything you’d expect in a Clock Master—Mr. Schneider told us how he was originally a civil employee for the Department of Social Services. He didn’t even work in the building, just passed by it numerous times. “And I got curious,” he says.

“At that time we were in the fiscal crisis of the 70s, things were falling apart, the image of the city wasn’t any good. We thought that a broken clock on top of a city building didn’t seem to be a very positive symbol of the state of the city or the image of its workers. We took it rather personally. So we fixed the clock.”

It didn’t matter much that neither Mr. Schneider nor Mr. Reiner had ever worked with clocks before. Mr. Reiner’s father was a watch maker, and Mr. Schneider explained, “I have good manual dexterity, I understood the principals. Everything on top of that I just learned.” At first they spent their own money, but eventually the City reimbursed them for their services, and in 1992, Mayor Dinkins lauded Mr. Schneider with his official title—along with a pension so his weekly maintenance wouldn’t have to stay voluntary.

Although the Howard Company went out of business in the 1960s, they provided the City with a set of replacement parts should anything break. Until now, only one piece has needed replacement—a clock wheel that the City’s machine shop fabricated. “They do very good work over there,” Mr. Schneider opined.

Otherwise, the clock keeps ticking away, accurate to within 10 seconds every month, a spectacular secret in the skies of Manhattan.