There was a business-as-usual atmosphere at the Old Ebbitt Grill last night as the venerable restaurant and drinking place counted down its last hours before closing its doors forever.

The staff carried on with a go-down-with-the-ship professionalism that seemed particularly suited to the Victorian ambiance of the restaurant, which has been in its present location since the 1920s and which traces its historical roots and its cherished artifacts back much farther than that.

And, indeed, the sadness expressed by both staff and patrons at the prospect that the Old Ebbitt would vanish from 1447 F Street NW was tempered by the knowledge that a new Old Ebbitt Grill is expected to open within a month around the corner in the 600 block of 15th Street.

But in the meantime ice clinked in glasses, tables were set and cleared, and indefatigable hostess Lori Fernand scrubbed offending fingerprints from the glass of the front door as the Old Ebbitt prepared to close.

In their attempt to maintain a stiff-upper-lip atmosphere, the 22 staff members may have been following the lead of assistant manager Matt Sheehan, who, as the final moments ticked by, vowed: "As long as it's humanly possible we'll keep it the Old Ebbitt Grill . . . it's always been."

And if some of last night's patrons were tourists who had never before been to Washington or visited the restaurant with its dark-wood wainscoting and famed mahogany bar, some were regulars who had strong feelings about the Old Ebbitt.

"This is an institution," said Gerry Kennedy, glancing up at the timbered ceiling and at walls supporting a stuffed sailfish, huge and grainy photographs of old Washington scenes, a set of antlers and the head of a buffalo--which wore a tin hat--and the head of a walrus, which did not.

Although he was pleased about plans for the new restaurant, Kennedy said, losing the old Ebbitt was "like losing an old friend."

Among others who made a point of visiting the Ebbitt on its last day were Alan and Denise Willsey. Alan Willsey, 31, said the restaurant had a special meaning for him, because he had proposed marriage there to Denise, 28.

The Old Ebbitt, which is to be torn down and replaced by an office complex, "has a warmth all its own," said still another patron, Velma Davis. The expected opening of the new restaurant was of some cheer to her, she said, but she added: "I'm only sorry they're not going to have a little corner that looks like this place."

The mahogany bar and some of the other interior features of the restaurant have been traced back to the Victorian-style Ebbitt Hotel, built at 14th and F streets in 1872. After the hotel was razed in 1926, the bar was saved and installed in the restaurant.

The bar in the new version of the Ebbitt is to be a copy of the old one, employes said last night. But they said the carved woooden bear that stood last night on a shelf behind the bar, and is said to have once been owned by Alexander Hamilton, will join most of the staff and many of the patrons on 15th Street.