Astonishing the audience -- and the auctioneer -- a pair of abstract watercolors, whose value had been estimated at less than $500, sold yesterday afternoon here for $82,000 in the downtown sales rooms of Adam A. Weschler & Son, 905 E St. N.W.

The angular abstractions, though attributed in the auction catalogue to "American (?) 20th century school," are actually long lost reasures of England's early avant garde. They were made in 1915 by the late Wyndham Lewis, who, by combining cubism and futurism created the art style that his friend, the American poet Ezra Pound, named "Vorticism."

One of the watercolors, "Design for Red Duet," is one of the most important images of the Vorticist movement. Not only was it reproduced in the second issue of "Blast," the short lived Vorticist magazine, it was also reproduced as the frontispiece of the catalogue of the first and last Vorticist exhibition held at London's Dore Gallery in June 1915.

Following spirited bidding, the two pictures were sold to William Wiltshire, a well know American art buyer, whose collection of Amercian folk art was sold recently at auction in New York for more than $400,000. Because auction houses nowadays charge buyers a 10 percent commission, they actually cost Wiltshire more than $90,000. William Weschler yesterday declined to say who had consigned them to his auction house. "I can say however that the consignors are delighted," he said.

A photograph of "Design for Red Duet" appeared in Weschler's catalogue. So did the notation that the watercolors, one 12 by 9 inches, the other 10 by 12 inches, were both initialled "W.L." and "dated 1915." That was apparently enough to aletrt ywiltshire and the New Ork dealer who was the underbidder. The presale price estimate in the catalogue was $300-$500."

Lewis, who thought Italian futurism too close to impressionism and the French cubism of Georges Braques and Pablo Picasso inadequately abstract, established a style so clipped and metallic that many thought his pictures and his writings looked as if they had been created by machine. He was born to English parents off the coast of Maine in the Bay of Fundy in 1884 and brought to England as an infant. After studying at Rugby and at the Slade School of Art in London he founded the Vorticist movement in 1913 just months before the start of the World War that helped bring it to an end. Lewis, who lived until 1957, later returned to representational art.

His novels include "Tarr" (1918); the trilogy "The Human Age" (1928); "The Apes of God" (1930); and "Self Condemned" (1954). He also published such nonfiction works as "The Art of Being Ruled" (1926), "Time and Western Man" (1927), and an autobiography he titled "Rude Assignment" (1950).

According to Richard Cork, a student of Vorticism, "Design for Red Duet" is, at least in intention, not entirely nonrepresentational. "The clue to its purpose is contained in an article called 'Wyndham Lewis Vortex Number One,' which appeared in Blast Number Two about 30 pages away from the Red Duet drawing," writes Cork.

Lewis, who believed man divided between pure intelligence and animal sensuality, advised his reader how to join the two halves: "You can establish yourself as a machine of two similar fraternal surfaces overlapping." e

"Be a duet in everything," wrote Lewis. "For the individual, the single object is . . ., you will admit, an absurdity. . . . There is Yourself; and there is the Exterior World, that fat mass you browse on. Do not confuse yourself with it."

He intended Vorticism's abstractions with their cutting curves and steeply angled lines to suck the observer into a new consciousness of the new machine age.