The discovery was pure serendipity: nosing around in a dusty bookshop in Scotland on a spring day five years ago, a pair of British booksellers stumbled upon a weathered red leather case engraved with the words "Designs for Blair's Grave." Opening it, they found 19 Romantic yet macabre watercolors — depicting angels, sarcophagi, moonlit graveyards, arm-linked spirits — rendered in a subtle range of grays, black and pastels.

Five years, one lawsuit and an export battle later, the watercolors — illustrations created in 1805 by the poet and artist William Blake for a 1743 poem — are being heralded by scholars as the most important Blake discovery in a century.

Yet to the consternation of many experts, all 19 are headed for auction this spring at Sotheby's in New York, which plans to break up the set and sell them on May 2 for a projected $12 million to $17.5 million. Estimated prices of the watercolors, each mounted on a 13-by-10-inch backing, range from $180,000 to $260,000 for the inscribed title page to $1 million to $1.5 million for the most intricate and compelling scenes.
That the works may end up scattered is a bitter prospect for Tate Britain, one of the world's most important repositories of Blake's works. Aided by a temporary export ban, the museum tried but failed to raise the money to buy them.

"That a group of works that have remained together for 200 years should be split up for financial reasons means that any opportunity for scholars to see them has evaporated," said Sir Nicholas Serota, the Tate's director.

Sotheby's counters that the set is incomplete anyway because one of the 20 watercolors that Blake originally produced for the poem, "The Grave," by the Scottish writer Robert Blair, was mysteriously separated from the rest. That work, "The Widow Embracing Her Husband's Grave," is owned by the Yale Center for British Art, which received it as a gift from its founder, Paul Mellon.

"It's not complete, so in a sense it's already been broken up," said George Wachter, director of old-master paintings for Sotheby's worldwide.

"The Reunion of the Soul and the Body" to "The Day of Judgment" to "Death's Door." Richly detailed and occasionally eerie, they are a highly individual interpretation of Blair's Gothic poem, a meditation on mortality and redemption. The poem, part of a poetic genre that came to be known as the graveyard school, proved so popular that by 1798 it had gone through 47 editions. By the time Blake created his illustrations, it was a classic in schools across England.

Since one of them is at Yale, it makes the most sense to do it this way," he said of his decision to auction them one by one.

Scholars and dealers who have been involved in appraising the watercolors disagree.

Martin Butlin, a prominent Blake scholar involved in the authentication process, said that selling them individually at auction was "absolutely philistine." "The seller has no regard for the integrity of works of art, only for money," he said. "As a group they tell a story." Titles of the watercolors range from "The Reunion of the Soul and the Body" to "The Day of Judgment" to "Death's Door." Richly detailed and occasionally eerie, they are a highly individual interpretation of Blair's Gothic poem, a meditation

on mortality and redemption. The poem, part of a poetic genre that came to be known as the graveyard school, proved so popular that by 1798 it had gone through 47 editions. By the time Blake created his illustrations, it was a classic in schools across England.

Aside from their significance as works of art — created in the same period that Blake was printing and reprinting his own "Songs of Innocence and of Experience," now part of the literary canon — the watercolors represent a painful episode in the artist's career.

In September 1805, the publisher Robert H. Cromek commissioned Blake to make 40 drawings illustrating "The Grave." He told the artist he would pay him 20 guineas for his work and select 20 for the final publication. Although Cromek was impressed by Blake's watercolors, he felt that the artist's style of engraving was not commercial enough. So he hired a well-known Italian engraver, Luigi Schiavonetti, to make 12 engravings based on Blake's designs. The decision was a slap in the face for the artist.

Blake completed the 20 watercolors and delivered them to Cromek, whose widow inherited them after his death in 1812. No one heard about them again until 1836, when they were included in an auction in Edinburgh and described as "A Volume of Drawings by Blake." They were bought anonymously for a mere £1.25 and disappeared from sight.