While the seemingly stable pre-Sept. 11 status quo had postmodern academics pondering the "death of history," a number of popular authors sought to re-examine humanity's past and present in the light of technological ripples caused by items ranging from codfish and screwdrivers to guns, germs, and steel. Sharing his peers' weakness for marketing-driven subtitles, Amir D. Aczel takes a similar trickle-up approach in his surprisingly fruitless The Riddle Of The Compass. No stranger to arcane fascination, Aczel has written audience-courting books on Einstein, the Kabbalah, and, in his best-selling Fermat's Last Theorem, math's most elusive brainteaser. The magnetic compass, however, proves more than Aczel can handle, both as a historian and as a storyteller. Though he calls the compass "the most important technological invention since the wheel" in his introduction, Aczel fails to make a convincing, much less interesting, case for such a sweeping statement in the undernourished 160 pages that follow. Part of the problem is the largely unknowable roots of the compass, which is commonly said to have originated in first-century China before showing up in Amalfi, Italy, around the 12th century. While the Chinese used mystically invested magnetism mostly for feng shui, the Italians employed it as a tool for navigation, which until then had relied on more seasonally dependent stars. Aside from drawing a handful of self-evident conclusions about expanding trade routes and sea-borne military conquests, Aczel doesn't offer much commanding evidence of the compass' world-changing importance. He fares a little better with its almost comically shrouded history, however, in material that deals with the confounding case of Flavio Gioia. Though a statue in Amalfi celebrates Gioia as the compass's inventor, Aczel shows how "Flavio Gioia" may exist entirely due to a comma error in a shoddy historical text. Not exactly the stuff of authoritative history, the tale ultimately works to expose the gap-ridden nature of Aczel's premise. Weighed down by gratingly redundant, dryly delivered prose, The Riddle Of The Compass does little more than prove that there is such a thing as the compass, we don't know much about it, and our ignorance isn't much of a loss.