The split between the lettered and numbered subway lines predates the creation of the Metropolitan Transportation Authority. Two private companies, the Interborough Rapid Transit Company and the Brooklyn Rapid Transit Company, ran the two divisions as separate subways until 1940, when the city purchased both and merged them into one system. But the same trains cannot run on both line divisions because the company that owned the lettered lines dug tunnels wider than those on the numbered lines.

The varied history of the two divisions still shows itself today in the competition for capital from the MTA, which modernizes only one division at a time. After two decades of using trains that break down more often than those on the numbered lines, the lettered lines may finally be gaining the technological edge.

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The numbered lines have historically been the first to receive technical upgrades from the MTA. While the numbered lines received new cars about five years ago, the C and the E lines are still equipped with trains that date back to 1964, a Transit Authority spokesman, Charles Seaton, said. A subway car is built to last about 35 years, but Mr. Seaton said the MTA’s maintenance procedures have extended their natural shelf lives.

Even by local standards, last Tuesday’s shoot, for “I Am Legend,” a forthcoming Will Smith disaster movie, was remarkable. “I Am Legend” is, in terms of size, length, and logistics, one of the most ambitious location shoots that has ever taken place in the city. Since shooting began, in October, “Legend” has been establishing a new precedent for the aggressive takeover of public space. The movie camped out in Washington Square Park for weeks in October and November, restricting access for most of that time, and occasionally setting off loud explosions in the wee hours. Tuesday night was the first of six night shoots on Dover Street, near the Seaport. In addition to simulated gridlock on Dover, there was to be a panicked evacuation across South Street, and a Black Hawk helicopter was to land on a two-hundred-foot barge in the East River.

At 5 P.M., more than a thousand extras were waiting in two huge heated tents that had been set up in a lot near some basketball courts. There were men and women of all ages, and lots of kids, some of whom were doing their homework at long wooden tables. The film is set in a plague-ridden Manhattan; the infected extras had hectic splotches of red makeup on their faces. Some of the extras (or “background artists,” as they were referred to by the P.A.s) were making seven dollars and fifty cents an hour, and would be working well past midnight. On Tuesday, the temperature was thirty-four degrees; by Friday it would be in the teens.

“I didn’t realize how big and dense and concentrated Brooklyn is,” said the Iowa native, who had apparently failed to look at a map before predicting that he could run the entire borough.

“Brooklyn is enormous.”

Perhaps by comparison to Iowa City, whose 230 miles of streets Jarvis once ran. As he learned, however, that’s nothing compared to Brooklyn’s 1,599 miles of mean streets.

Jarvis had never spent time in Brooklyn until he moved here to be with his girlfriend. Like any newcomer, he figured the best way to get to know his new home would be to get out.

“Talk about not thinking things through,” said Jarvis, whose presence has been noticed everywhere from Greenpoint to Bensonhurst.

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On Friday, Jan. 19, Jarvis hit the halfway mark and started a much-needed break.

He claims he’ll be back on the roads in six weeks — but it’s no longer clear if he’ll make it.

The main attraction is Congregation Shomrei Shabbos, a 24-hour synagogue where a service begins every 15 minutes. What started more than three-quarters of a century ago as a tiny congregation has grown into a mainstay of this community: transit hub, soup kitchen, community center, bookstore and prayer hall all in one.

The late-night traffic generated by the synagogue has spilled onto the streets, so much so that over the past few years a neighborhood has literally grown up around it. Restaurants and stores are open long past midnight. Peddlers vie for street space in the wee hours. Religious music streams from a small boombox. Men stop their cars in the middle of darkened streets to announce the birth of a child.

Even in a city renowned for the hours it keeps, the late-night liveliness here is remarkable.

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Thanks to all this activity, the once-inconspicuous synagogue is now a trigger for local nightlife.

“Real estate surrounding the synagogue is in high demand,” said Mendy Handler, owner of Cellular 4 Less, one of several local businesses that stay open past midnight to attract late-night synagogue-goers. His busiest hours are from 6 p.m. to midnight. “People can drop off their phones to be fixed while they are praying next door,” said Sol Oberlander, the store’s manager.

New York is the last state to update its machines, and the latest delay comes amid growing questions about the work of a laboratory that was hired to help test the machines being offered by five bidders.

Based in part on the problems with the testing lab, the New York State Board of Elections has pushed back its deadline for certifying which machines would be acceptable until at least May.

Given the months it would take for counties to acquire the machines and train poll workers, “that would make it impossible to replace anything more than a few isolated machines for the 2007 elections,” said Douglas A. Kellner, a board co-chairman.

Mr. Kellner said it might be possible to have the new system ready for the presidential primary in March 2008. An association of county election officials passed a resolution last week urging the state to wait until 2009, and Mr. Kellner said most board members agreed that it would be better if the state did not have to make such sweeping changes amid the high turnout of a presidential election.