The National Gallery of Art yesterday announced that the ruins of two large Rose Period Picassos -- both long considered lost -- have been found by X-ray analysis underneath the surface of his "Family of Saltimbanques" (1904-05), which the gallery has owned since 1962.

The discovery alters our understanding of Picasso's Rose Period. In addition, says E. A. Carmean, the gallery's curator of 20th-century art, the work we see today -- with its odd sense of remoteness -- is a metaphorical account of one of the strangest episodes in Picasso's life.

The investigation was prompted by the gallery's decision to recognize the centenary of Picasso's birth by hanging an exhibition of his circus pictures, of which the "Family of Saltimbanques" is among the grandest. That show will open here on Dec. 14. In reexamining the history of the painting, gallery officials came upon two remarks -- one by Fernande Olivier, once Picasso's mistress; the other by Andre Level, the first owner of the "Saltimbanques" -- both claiming that the canvas had been much repainted. Their contentions, says Carmean, had long been overlooked.

The X-ray discovery of "Circus Family," a 12-figure group scene, and of "Two Acrobats," a second composition done on the same canvas, suggests a new chronology for nearly 100 studies, sketches, prints and drawings whose sequence, Carmean says, was previously unknown. Scholars can now trace in detail the winding path Picasso followed as he left the poverty and darkness of the Blue Period for the Rose Period's warmer light.

One reason that the picture was revised so often is that Picasso, in 1905, was so poor that he could not afford to discard an 83-by-90-inch canvas.

The picture, in its first state, was a study of maternity -- four mothers and four babies were among its dozen figures. By the time the work was finished, none remained.

Carmean contends that the woman with the straw hat who sits in isolation in the picture's lower right hand corner is Fernande Olivier. The harlequin at the left, who looks at her so coldly, is the young Picasso. The faceless little girl whose hand the painter holds is, says Carmean, the orphan that the two of them adopted -- on a trial basis -- in the summer of 1905.

It is known that Olivier, who could not bear children, took a little girl from a nearby orphanage and brought her to Picasso's Paris studio. Then, a few days later, deciding that she lacked "maternal fiber," Fernande changed her mind and sent the weeping child back.

Ann Hoenigswald of he gallery's conservation department took some 50 X-rays of the "Family of Saltimbanques," and the layers of paint were analyzed. The process revealed that: the harlequin at one time wore a tall silk hat and a long dark overcoat; a young acrobat in colored tights once balanced on a ball above the figure of Fernande; and the strange long-handled basket that the little girl is touching was once a friendly dog.

As the picture filled up with happy figures -- balancing acrobats, playful children -- it seemed a portrayal of companionship and family. "But Picasso at the last minute changed his mind," says Carmean. "He introduced Fernande -- and that mood of poignant loneliness. It is as if he suddenly decided to move against the grain." Though we know from their costumes that those saltimbanques are circus folk, acrobats and jugglers, none of them is smiling. Most of them stare coldly at the strangely friendless figure of Fernande.

The "Circus Family" was known until recently only from a watercolor study in the Baltimore Museum of Art, and from a drypoint print Picasso made in 1905. Studies for "Two Acrobats" also have survived, but scholars never knew to what painting they referred. "We can read this painting now as an index to Picasso's work of 1904-05," says Carmean.