Urban Sundial.(Manhattan's grid system streets)(Brief Article)

The biggest timepiece in Manhattan is seven miles long and a mile or two wide. For counting the smaller units of time-seconds, minutes, hours, days, weeks, months, seasons-it is worthless, but it marks with tolerable precision the summer solstice. This chronometer is the grid of the city's streets.

Unlike many settlements in North America, which were laid out in grids from the beginning, New Amsterdam developed in an ad hoc tangle, still preserved in the ant tunnels of the financial district. As the town expanded beyond Wall Street, it continued to lay out its streets haphazardly. It wasn't until 1811 that New York caught up with modernity; then, like many parvenus, it went overboard. A three-man commission, including Gouverneur Morris, the peg-legged aristocrat who had written the Constitution, slapped a mesh of rectangles over Manhattan, from 14th Street on up to the island's remote wooded heights. Avenues, they decreed, would run up- and down-town, while the narrower and more numerous streets would run at right angles to them. As the city grew into its new pattern, preexisting lanes and paths that violated the grid were blocked up, and the scattered buildings that lined them torn down. Only Broadway, the old Indian trail that angled across the island, survived the rationalizing process, though the commissioners had wanted to eliminate it too.

As befits New Yorkers, the commissioners were motivated by economic efficiency. "Strait-sided and right-angled houses," they wrote, "are the most cheap to build . . ." Edwin G. Burrows and Mike Wallace, two academic historians of New York, find in the grid a political program as well, "a democratic alternative to the royalist avenues of Baroque European cities." But a third aspect of the scheme-probably unlooked for-is its alignment with the sun.

Manhattan is an unusually straight piece of real estate-it points like the digit of an alien's hand-and New Yorkers think of it as pointing from south to north. But it actually skews to the north-northeast as it goes uptown. The result is that the cross streets of the grid, which supposedly run "east" to "west," actually run east-southeast to west- northwest. And that means that, at the latitude of New York, from about mid June to the Fourth of July-the envelope of the summer solstice-the sun sets precisely at the "western" end of the crosstown streets. Ages hence, archeologists will surely conclude that the city's planners were not thrifty democrats, but Wiccans and Druids.

As the days lengthen, the time comes when the setting sun suddenly makes it around the corners of buildings. The light in New York is often remarkable-there are many days when the sky seems hallucinogenic, until you realize that this is a decadent's perception: It is only blue, Eden-blue. But given the height of the buildings, the light usually has to be enjoyed by looking up. Now, in midsummer, it enfilades the city, pouring through its undefended flanks. ...