Here in Mount Pleasant we have a blessing of which many suburbanites would be jealous: Our power lines are underground. Thus we rarely if ever have power outages. Though I am grateful for this, I'm still curious about when our power lines were buried and why.

Dunstan Hayden, Washington

Pepco couldn't say exactly when Mount Pleasant's power lines were buried, but Bob Dobkin, the company's spokesman, suspects they've always been buried.

As early as 1888, city administrators were bemoaning Washington's "numerous and unsightly poles." Electrical, telegraph and telephone wires draped the streets like so much al dente spaghetti. An 1892 report recommended burying all lines in what had been the City of Washington -- the diamond that was roughly north of the Anacostia River and south of Florida Avenue (then Boundary Street). (The report sniffed: "The Western Union Company stands alone in its persistent opposition to underground wires in the District.")

A beautiful foldout map in the report shows how the conduit would be laid: four ducts on 16th Street, eight ducts up 14th Street, 16 ducts running along F Street, etc.

According to Pepco's official company history, "100 Years of Matchless Service," its predecessor, Uselco (the United States Electric Co.), pioneered the country's first underground lines. At the close of the 19th century, Congress passed an act mandating underground lines as the standard for the city, recognizing, according to the history, "that subterranean lines were less susceptible to the vagaries of the weather and wouldn't adversely impact the appearance of the nation's capital."

Mount Pleasant is outside that original diamond. But it's so close to it -- barely a half-dozen blocks north -- that it's easy to imagine Pepco simply laying the lines underground as the neighborhood was developed in the late 19th and early 20th centuries.

Said Bob Dobkin: "It's underground all the way to Dupont Circle and Adams Morgan. . . . Georgetown is underground. When you get to the far reaches, you get back into aboveground. In the residential areas, it's overhead."

Answer Man suspects that the city's rapid growth, not to mention the hopscotching way in which houses and neighborhoods were built, forced Pepco to resort to overhead wires, which are cheaper and easier.

And that's the way it stayed until the early 1970s, when laws were passed in some jurisdictions that required new subdivisions to have underground power lines.

"It's easy to do it when land is being developed," said Bob. "It's harder to do it when land is being redeveloped. You basically have to dig up the streets. You also have to trench to every home and business. It would be, of course, very costly and very damaging to what's there."

How costly?

Estimates range from $1 million a mile to $3 million a mile. Compare that with $10,000 to $250,000 to install overhead power lines.

"We've met with local jurisdictions to discuss undergrounding," Bob said. (That's what they call burying existing power lines: "undergrounding.") "Usually when you explain what the costs are, they seem to lose interest."

One reason is that if the lines are going to be buried in only one neighborhood, that neighborhood has to foot the bill. The cost can't be spread among all the ratepayers. (Well, it could, but that wouldn't be fair, would it?)

The issue of burying power lines came up most recently after Hurricane Isabel, when tree limbs made a mess of the electrical system in the Washington area. Would buried lines have helped?

Maybe, say the experts. Yes, buried power lines can't be taken out of commission by tree branches, but they are susceptible to outages because of flooding and corrosion, not to mention people who dig in the wrong place. Also, underground wires don't last as long as overhead wires.

Bob Dobkin said 59 percent of Pepco's lines are underground, and 41 percent are overhead. In the District alone, 70 percent are underground.

All of the blue mailboxes in the District list a morning pickup time of 10 a.m. How does the U.S. Postal Service accomplish such an amazing feat of coordination?

Max Ramirez de Arellano, Washington

Answer Man envisions something akin to synchronized swimming: Starting about 9:57 a.m., Postal Service personnel start gathering at the 1,395 boxes that dot the streets of the District. They scrutinize their watches and at the precise stroke of 10 -- in a solemn ceremony dating back to the days of Benjamin Franklin -- they unlock the mailboxes and remove their contents.

Alas, it is not nearly so precise. The pickup times posted on the boxes are the earliest time at which mail will be collected, said Postal Service spokeswoman Deborah Yackley. "It's probably picked up sometime shortly thereafter," she said. Deborah said 78 carriers collect mail from the boxes in Washington.

One morning last week, Answer Man's assistant staked out a pair of mailboxes at 16th and P streets NW. The 10 a.m. pickup was at 10:50.

Unfortunately, she couldn't be in 1,395 places at once, so we can't say for sure when the other boxes were emptied.

Julia Feldmeier helped research this column. Mail questions about things you've encountered in the area to John Kelly, The Washington Post, 1150 15th St. NW, Washington, D.C. 20071. Or save 37 cents and write