It is an engraving, showing a scene in the District--with a view north along 15th Street NW. In the background are pedestrians, street lights, buildings and four automobiles. In the foreground is the U.S. Treasury, one of Washington's three oldest federal buildings.

Although the engraving has been printed by the billions, it is still prized and avidly pursued. That's because it's the image on the back of the $10 bill, a kind of green-ink picture postcard that, since the 1920s, has brought a glimpse of a downtown Washington street to the far corners of the globe.

Now, as part of what a government spokesman calls "the first distinctive or noticeable change" in U.S. currency since 1929, the bill design is being phased out. New $100, $50 and $20 bills have already been issued, and a new $10 bill will go into circulation the middle of this year. A new $5 bill also will appear.

Like the current $10 bill, the back of the new one will show the Treasury building.

But the urban background will be gone. Fifteenth Street does not appear. The autos have been eliminated. There are no pedestrians and no other Washington buildings. The strip of street once known--because of the banks and brokerage houses that lined it--as Washington's financial district, the city's Wall Street in miniature, is vanishing from the nation's legal tender.

Larry Felix, a spokesman for the Treasury Department's Bureau of Engraving and Printing, said last month that the agency hasn't printed any old fives and tens since earlier last year. Actual printing, as opposed to circulation of the new bills, should begin about March, he said.

The bills not only show images of the District, they are also among the best-known objects made in the District.

Some of the nation's currency is produced in the bureau's plant on 14th Street SW, a mandatory stop for many tourists. Some is printed in a newer plant in Fort Worth, Felix said.

The new fives and tens, he added, "will be done in both places."

The new bills are being introduced as part of a program to foil counterfeiters. The new bills have many features intended to defeat color scanners and other high-tech printing equipment.

For example, the bills are printed on "denomination-specific paper," Felix said.

"What this is all about is making our money as secure as it possibly can be," said Treasury Secretary Lawrence H. Summers at a recent ceremony at which the redesigned $5 and $10 bills were displayed.

The new bills, he said, are intended to be "not only traditional but also ready for the 21st century."

The same famous Americans depicted on the front of the old $5 and $10 bills, Abraham Lincoln and Alexander Hamilton, respectively, are shown on the new ones. But the portraits of them are different.

Similarly, an engraving of the Lincoln Memorial will still be on the $5 bill. But the building images will be "clearer and sharper," Felix said. The bills have been redesigned to be "really consistent with the basic architectural thrust of the new currency," which he said is somewhat "more geometric" than the earlier bills.

In the case of the $50 bill, which shows the U.S. Capitol, the new view is of the west front. The older bill shows the east front. On the new $20 bill, the view is of the north side of the White House. The old bill showed the south side.

The current $10 bill shows the south and east sides of the Treasury building. The new bill will show only one side.

It is either the north side or the south side, but it is not clear which, said Felix.

"We're not quite sure," he said. The important thing is that it represents "the essence of the Treasury Department" building.

The new bills, although replete with features to foil counterfeiters, do not rely on such artistic embellishments as spirals, flourishes and curlicues. Instead, the design appears to emphasize clean, bold lines. The straight-ahead look at the Treasury conforms with this spirit, Felix said.

In addition, he said, in designing new bills, authorities were "careful not to date" them, by showing features that might not remain in place or that might change in appearance over time. A close look at the White House today shows a variety of structures on the roof, including antennas. But in the spirit of the redesign, Felix said, designers "took the antennas out."

The $10 bill currently in circulation has its own quirkiness. The four automobiles shown on it have the boxy angularity associated with many cars of the 1920s. One Treasury spokesman said they are sometimes believed to be one of the famous vehicles of that age, the Ford Model T.

But, according to Treasury, it would not be proper for the government to favor one product over another on its currency. As a result, the Treasury Department said, the vehicles are composites; "the cars in the design are of no specific make or model."

In the current design, the distinctive marble bank building on the northwestern corner of Pennsylvania Avenue and 15th Street NW is clearly visible. Like the nearby Treasury department itself, this is one of Washington's historic structures.

Reportedly it was once lauded as "the handsomest banking building in the United States."

Built in 1905, it was once the headquarters of the American Security Bank. After a series of banking mergers, the building now bears lettering identifying it as a branch of the Bank of America.

At one time, advertising for American Security billed it as the bank that was "right on the money"--which, being across the street from Treasury Building, it was.

Given Treasury's concern that the currency not favor any brand of cars, it was suggested that the building in the background be eliminated for a similar reason.

Felix squelched that idea. "No, no," he said.

The "driving force" behind the new designs was security and the "basic architecture" of the entire bill, he said. This is characterized by cleaner lines, a more geometric look and a "very modern appearance." The introduction of the new $10 bill does not mean the current one will disappear, however. As they show up at Federal Reserve banks, they will be taken out of circulation and replaced, but they will retain their value and are not being recalled.

In the months since the first of the new series of bills went into circulation, occasional criticism of the new designs has surfaced. The currency has been described as looking like play money, or Monopoly money.

"Clearly," Felix said, "people have to get used to it." And he believes they will.

"Recently," he said, "I was in a bank and I heard people say, 'Hey, can I get the new ones?' "

"It's a matter of familiarity and acceptance," he said. "I think the money will spend."

CAPTION: Left, the back of the new $10 bill. Right, the back of the current $10 bill. The new $10 and $5 bills are being introduced as part of a program to foil counterfeiters.