One of the many pleasures of going to art galleries regularly is that in addition to the formal exhibitions up front, art dealers often display unexpected gems off to the side, in project spaces, offices or even behind the reception desk: lost bits of history and unfamiliar early works by this or that artist. Recently, in the lull before the onslaught of this week's art fairs, one of these isolated treasures provided a useful reminder about close looking. On a visit to the George Adams Gallery in Chelsea, I came across a smallish work that Mr. Adams has put on view in a side gallery: a smooth, darkish painting of a female nude asleep on an empty beach, with the nose of a small sailboat nudging in from the right side. Mr. Adams invited me to guess its maker. [ABSTRACT FROM AUTHOR]