The Track Edge Over Manhattan

In the year leading up to the 1925 eclipse astronomers knew that the border of the track would slice through New York City, but they were not sure precisely where. Looking just at Manhattan, it was clear that the track limit would pass near Central Park, but as to whether the absolute edge would be to the north or the south of it was another question.

First, let us think about the orientation of the track. It approached the city in a broad arc from the extreme west of New York state, and so it was angling down from somewhat to the north of due west. It happens that the crosstown streets in Manhattan have a similar orientation, tilted by about 30 degrees away from a precise west to east line. This meant that the track path and the cross streets were close to parallel. That was a fortuitous thing, because the street number where any observer may have been stood would on its own give a good indicator of the track limit.

Back in Chapter 3 we met Ernest Brown, an astronomer at Yale. Like most such professionals he planned to observe the eclipse from near the central line, and of course New Haven, Connecticut, was well positioned for that (see Figure 10-3). Brown, though, very much wanted to know where the edge of the track lay because this would assist him in his research on the theory of the lunar motion. Therefore he appealed to all New York residents to note where they were—on the roof of their apartment building, for example, or at a particular road intersection—and report whether they saw a total eclipse or not. In addition, observers

FIGURE 10-3. Snow surrounds the instruments set up on the Yale University campus to observe the January 1925 eclipse.

were stationed at every other intersection along Riverside Drive between 72nd and 135th Streets.

One might imagine this was unfair in that Brown was in effect asking people not to go into the zone where totality was assured: north to Yonkers or White Plains. The fact is that many of them in any case could not afford the time off work that would entail, or the traveling expense. Certainly it is true that many people south of 80th Street were disappointed not to witness totality. To the contrary, however, those very near the periphery of the track—even those slightly beyond it—actually saw a far more startling set of phenomena than those close to the center line, some tens of miles north.

Elsewhere we have described the diamond ring effect and how you are more likely to see this spectacle for a prolonged period if you happen to be located near the track edge. That is precisely what occurred in 1925. In fact the term "diamond ring" used to describe this appearance was coined by NewYorkers, when journalists asked them to describe what they had seen in their own words. It has since passed into the general vocabulary of eclipse watchers.

The result of the eyewitness accounts did enable Brown to work out precisely where the track boundary lay. It was between 95th and 97th Streets. Although it might seem that the volunteer observers had sacrificed themselves for Brown's experiment, in fact they got a far better experience than he did, even if his period of totality lasted longer.

There was great excitement, then, that Saturday night after the eclipse had passed by. Nowhere was this more so than in Chinatown. The eclipse that morning was when the Moon was at conjunction. Thirty-three hours later, as the Moon set in the west, it would be visible as a slender crescent. That meant that January 24 had been predetermined as the last day of the Chinese year, the Year of the Rat, heralding celebrations for the New Year beginning the next day.

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