Faced with a shortage of masterpieces to sell, Israel Sack began a brokering program last spring.

"We're addressing the demand for an alternative to the auction houses," said Nancy N. Johnston, the director of operations at Israel Sack.

Harold Sack of Israel Sack, the 57th Street dealer, said that the clock appeared to have been made earlier than the cabinet.

The authors point out, for example, that Israel Sack and his sons have always refused requests to authenticate furniture that has been purchased from other dealers.

She is the librarian at Israel Sack, the American antiques dealer in New York.

Israel Sack has a Philadelphia Chippendale mahogany side chair with shell details and superb outlines - and a price tag of $450,000.

Mr. Serri's dressing table has twice passed through Israel Sack, the renowned New York gallery.

"Israel Sack has the best of the best - that's where I want to die," he said.

Israel Sack was a brilliant marketer.