OFF THE MAP

Excerpts from the Lewis and Clark journals—framed between a brief ``Prologue'' (on the purpose of the expedition), plus Jefferson's letter outlining guidelines for exploring the Territory, and an equally brief ``Epilogue'' (on the trip back and the ultimate fates of major participants)—that sufficiently suggest the hardships and heroism of the journey. But though this is authentic source material, it's merely a taste—the full journals run to eight volumes. Meanwhile, many episodes here are so truncated as to be enigmatic, while others tantalize by not reporting outcomes of events described. The Roops don't even, usually, indicate which explorer authored the brief entries. Tanner's realistic oils, on canvas mimicking a parchment ground, are attractive, but his endpaper map also needs more details. Since there are some telling incidents here, this will have some use as a supplement to secondary sources; but a more extensive sampling, with fuller explanation, would have been a good deal more valuable. (Nonfiction. 8-12)