The summer had not brought Morrison and Rose-Redwood success, but it had delivered adventure. The two had climbed to the summit of Marcus Garvey Park, formerly Mt. Morris Park, at 120th Street and Fifth Avenue. That particular invisible intersection took them up a steep, slippery slope and into a campsite. The occupants “were not the Patagonia-wearing-type campers,” Morrison remarked, so he and Rose-Redwood had scrambled quickly away. Working at a long wooden table under the soaring ceiling of the New-York Historical Society library, they had struggled to decipher old documents and sketches. And they had observed the transit of Venus, a rare event during which the second planet can be seen as a small dark dot sailing across the bright surface of the sun. Transits occur in pairs, about eight years apart, every century or so. The 1761 transit was observed by Charles Mason and Jeremiah Dixon shortly before they surveyed the Mason-Dixon line. Morrison had brought his theodolite, a surveying instrument with a telescope, into Central Park in the early morning and set it up at Belvedere Castle.
Rose-Redwood and Morrison had been working together and exploring invisible intersections since late spring, when they met at a lecture given by Rose-Redwood about New York City’s 1811 grid plan. The grid plan—much adored and much abhorred, although the abhorrers have been perhaps more vocal—established a trellis for New York City to climb as it grew north from what was then North Street, now Houston Street, to 155th Street. In 1806 the city government had determined that New York was expanding too rapidly, without blueprint. Hoping to avoid the passionate, bitter debates that erupted whenever land sales or boundary issues arose, city politicians asked the state legislature to help. The politicians in turn recommended three commissioners who envisioned grid on unprecedented scale. With relatively few exceptions, most conspicuously Central Park, the kinked off-kilter route of Broadway, and the D.C.-like angle of St. Nicholas Avenue, New York City flowed into that form, like batter flowing into the grooves of a waffle iron.
Morrison and Rose-Redwood wanted to find a token from imagined New York, from the years when New Yorkers gave form to the dream of a grand metropolis. They wanted to find physical evidence for a plan some scholars have called “the single most important document in New York City’s development.”
“I think I am the one who found it,” Rose-Redwood later recalled. “But it really doesn’t matter.” The three seekers had fanned out around the GPS unit, which indicated that they were in the middle of yet another invisible nineteenth-century intersection, one now teeming with bicyclists, joggers, and horse-drawn carriages, one redolent with the prickly smell of manure. Several minutes of searching later, Rose-Redwood gave a shout. A dark brown bolt, about 1 inch square, jutted 3 inches out of a rock. It sat in a bed of lead. “We were really quite euphoric,” said Rose-Redwood.
They examined the bolt, discerning faint marks on its flat top—a kind of surveyor’s signature found on most such markers. They debated the bolt’s legitimacy. Rose-Redwood felt 85 percent sure it was a grid bolt but wondered if they could get a chemist to test the metal and perhaps date it so they could be positive. “What we need to be very cautious about is that there have been many surveys in Central Park since it was laid out in the 1850s and 1860s,” he fretted. “I mean, we might find something that is from a different survey.” Morrison was 99 percent sure, because to his mind, the location was too perfectly grid-aligned to be coincidence; they had found other bolts in the park that summer, but none of them corresponded to an 1811 intersection. They also began to feel protective of the bolt. They have suggested to the parks department that a small clear case be set protectively over it. The bolt would sit inside its box, upon its boulder, amid its city, which would sprawl around it, no longer wild, like poet Wallace Stevens’s jar upon its hill.