Sometimes in a sea of numbers, it takes just one stat to astound you into getting the picture: In one of the New Towns of Hong Kong, Tseung Kwan O, some 350,000 people live within four square miles. They live in towers that vary from 57 to 62 stories. Here’s another stat: 80 percent of them live within five minutes of a rail station. How about that for a mass transit success story?

Such numbers tell a lot about Hong Kong in 2009. It’s the most densely occupied major city in the world, it’s constantly growing upward, and it possesses key similarities as well some stark differences with New York City.

A skyscraper race to the sky is taking place across parts of the globe right now – epitomized best, perhaps, by the building of Burj Dubai in the United Arab Emirates. It’s not an easy race to grasp. For decades the construction of such a tall tower in this country, like the Empire State Building or the World Trade Center, was very momentous. Now and with the focus shifting to Asia and the Middle East, a huge new “tallest in the world” is popping up every several years, many cities are building supertall structures that tower ever higher, and sometimes even veteran skyscraper aficionados feel like it’s all a jumble.

The current exhibit at The Skyscraper Museum in New York, “Vertical Cities: Hong Kong, New York,” allows one to understand the skyscraper mania by exploring two iconic “vertical metropolises.” It examines the needs, societal forces, designs, and scale of building taller and taller. It wasn’t quite like walking around Hong Kong, but through the exhibit’s photographs, architectural drawings, film, computer animations, maps, brochures, and large-scale models, it was enough to get a real picture – and maybe even to feel blown away by it all.

The exhibit calls Hong Kong and New York the world’s “most similar skyscraper societies.” Both feature island cities with excellent and busy harbors, and both evolved into dominant centers of finance and commerce. New York and Hong Kong have had defining moments of development that propelled the building of many skyscrapers through which entrepreneurs and designers channeled economic growth and became super-competitive: New York in the 1920s and 1960s, and Hong Kong in the mid-1980s through 1990s to today.

The exhibit, which runs through February 2009, is the second in a cycle of three exhibits, entitled “Future City 20 | 21,” that juxtapose a retrospective of American visions of a skyscraper city with a look at Chinese cities today. The first exhibit, “New York Modern,” depicted how the dreams and prophecies of a skyscraper city took shape in the early 20^th century.

As New York expanded upward, these fantasies and ideas of architects and designers exploded in the 1920s, with visions of monumental towers, multilevel highways, aerial transport, skyscraper bridges that would span the rivers, and hanging gardens that would spread over the central business district. New York passed London in 1925 to become the world’s most populous metropolis, and its dramatic growth and congestion served to both motivate and foster these visions, according to the earlier exhibit.

Fortunately for anyone who loves the brownstones and the intimacy of the neighborhoods that retain plenty of 19^th and early 20^th century character, the fantastic visions of a New York that would be drastically rebuilt and fairly unrecognizable did not come to fruition, as Museum Director Carol Willis noted in the first exhibit. The notion of skyscrapers defining cities, however, took hold, and New York became a kind of prophecy of the world’s skyscraper cities of the late 20^th and early 21^st centuries, such as Hong Kong. The visions of Raymond Hood and Hugh Ferriss in the 1920s for groups of gigantic towers linked by public transportation, for instance, have come to pass in Hong Kong’s super-efficient mass transit system.

Clustered to the Max

If there is a word that captures the living experience the Vertical Cities exhibit portrays of Hong Kong, it is density – millions of people packed in a very compact area. It’s matched by a density of numbers in the exhibit, ranging from population of the various parts of Hong Kong to number of high-rises, various tower heights, and slenderness ratios of skyscrapers, etc. Sorting through it all takes a little work, and the effect of seeing Hong Kong’s sheer mass of people told in numbers, images, and scale models is big. “Intense!” pronounced a fellow museum visitor.

Hong Kong’s 7 million inhabitants live at an average density of 70,000 people per square mile, which is equal to Manhattan’s. However, Hong Kong is a mountainous territory that primarily “piles” people – in the words of the exhibit notes – on one-quarter of its land and reserves about three-quarters for nature or agriculture, while three-quarters of New York City is built and one-quarter is open space or parkland.

Parts of Hong Kong have densities of 90,000 people per square mile, vertical density in the extreme. It has a hugely crowded commercial core tucked on flat waterfront land between the lush green hillsides and the city’s harbor, suburban-type New Towns marked by massive high-rises, large pedestrian bridges, vertical shopping malls, and many pencil-thin towers. It has 7,838 high-rises, just over 2,000 more than New York’s 5,814.

Another key difference between Hong Kong and New York: New York’s buildings are in relationship to the streets, but in Hong Kong, the siting of towers has little relationship to the streets they face. Instead, the Chinese practice of feng shui largely guides the orientation of skyscrapers and multi-building complexes. The exhibit could have delved into this far more, and it would certainly be an excellent topic for another exhibit.

It is one thing to see skyscrapers in the central core, but quite another to look at them climbing up the slope of beautiful Victoria Peak. The Skyscraper Museum’s photographs, maps, films, and satellite images offer a lot of ways to virtually experience the sensation of such a vertical place. I found myself wanting to experience walking the streets and through the markets in some of the tower-dominated areas.

A Ride Up the Mid-Levels Escalator

One of the best ways was watching a video that showed Hong Kong’s Mid-Levels Escalator, the world’s longest open-air covered escalator. Climbing about a half-mile and containing a combination of escalators, ramps, and moving sidewalks, it snakes from the IFC Mall in the downtown to a residential neighborhood of high-rises up in the hills. Watching it, I felt like I was within a vertical cocoon, coming within inches of apartments, seeing the street markets underneath, passing by galleries.

The Mid-Levels Escalator has become a favorite of visitors, which says something not only about this inventive people-mover, but about Hong Kong’s buildings. As architect and Chinese University of Hong Kong professor Laurence Liauw Wie-Wu explains in the exhibit’s notes, “Hong Kong lacks sites of genuine architectural value, so this escalator ride is one of the top 10 tourist attractions.”

Lacks sites of genuine architectural value? Those words pop out. Certainly, as I scan the photos of Hong Kong’s skyline and look at skyscraper models, little enchants my eyes (with the exception of I.M. Pei’s Bank of China tower). The exhibit, however, is fascinating. It makes me want to visit Hong Kong, and the exhibit’s deluge of data provides as many questions as answers. What is the living and walking experience of this vertical city? What buildings or skyline sights thrill those who live or visit Hong Kong? What is it like to shop at a mall many stories in the air, or ride an open-air escalator that runs for about a half-mile?

What is most clear is the skyscraper race will only intensify in the 21^st century. Ultimately, a vertical city means something even more tall, monumental, and massive in 2009 than 1925 or 1980.