COMPASS

A Story of Exploration and Innovation

By Alan Gurney

Norton. 320 pp. $22.95

Stories about ingenious devices that have permanently altered human existence are endlessly interesting, and if told by the right person can attract substantial readerships and audiences. Dava Sobel's "Latitude," Henry Petroski's "The Pencil," Amir Aczel's "The Riddle of the Compass" -- these books and others like them have been deservedly popular and have enhanced general knowledge of how things we take for granted were invented and perfected, usually over many generations of hit-or-miss guesswork and/or shot-in-the-dark scientific inquiry.

Alan Gurney's "Compass" clearly was written in the hope of cashing in on readers' fascination with these stories, but it is almost impossible to imagine that it will succeed in doing so. For one thing, it is far more limited in scope than Aczel's book, and far less informative. For another, it is simply a lousy book: sloppily written in an aren't-I-cute? fashion, turgid in its efforts to explain complicated scientific matters, and almost breathtakingly provincial. Read "Compass" and you will imagine that the device about which Gurney writes was almost entirely Made in England, when in fact all reputable accounts make plain that its origins trace back to China in the 11th century or earlier, to which Gurney devotes scarcely two of his more than 300 pages.

"This is the story of man and the marine magnetic compass," Gurney writes; "the story of an instrument which guided countless sailors across seas and oceans into the unknown. The story of an instrument so precious to northern seamen of the sixteenth century that any man found tampering with the compass or its magnetizing lodestone had his hand, by law, pinned to the mast with a dagger, the even more painful result being a split palm as the offender, to gain freedom, dragged his hand down against the blade."

Coming as it does in the book's prologue, that paragraph suggests a dramatic narrative to follow, but there's no drama in Gurney's telling of the tale. "Compass" wanders aimlessly through the centuries, pausing from time to time to tap the shoulder of some ingenious Brit who almost, but not quite, solved the problems of magnetic variation, compass deviation and other difficulties that presented themselves as scientists and technicians tried to build a compass that could be installed aboard ships and still -- despite ships' constant movement and the magnetic iron aboard them -- point accurately toward true north.

Gurney begins with Alexander Neckham, "an English scholar-monk, [who] was the first to record a metal needle being magnetized by a lodestone and then used as a marine compass," though three pages later he concedes that "the Chinese, centuries earlier than any mention of the fact in Western literature, were aware of the directional properties given to a metal needle when touched by a lodestone." Never mind. After two pages of that, a brief nod to the French and the Italians (the latter, in Aczel's book, are given due credit for their important role in the compass's development), it's on to John Dee, "an Elizabethan scholar, mathematician, astrologer, alchemist, geographer, magus, and spy," and others -- Robert Norman, William Gilbert, Edmond Halley, Gowin Knight, John Smeaton, Matthew Flinders, George Airy, William Thomson, et cetera, et cetera -- all of them sons of this blessed plot, this Earth, this realm, this England.

Sure, England was the world's dominant sea power for most of the time that the compass slowly evolved from a crudely magnetized needle into the gyrocompass and inductor compass of today, so it stands to reason that much of the research and experimentation was done by the British. But the Anglocentric interpretation embraced by Gurney oversimplifies historical truth and ignores important work being done in other places at approximately the same time. As the title of Aczir's book makes plain, the evolution of the compass is a "riddle" that will never be completely solved, but the one certainty is that many people in many countries contributed to it, and that no one can hope to write a reliable account without including the most important of them without regard to nationality.

Gurney actually seems to be more interested in shipwrecks that were caused by inadequate compasses than in the compasses themselves. He begins with "the worst shipwreck disaster ever suffered by the Royal Navy" -- the crash into the granite reefs of the Scilly Islands of four ships in October 1707, with the loss of about 2,000 men -- and proceeds dutifully from one calamity to another: the Apollo in 1803, the Thetic in 1830, the Reliance "a few years later," the Tayleur in 1854. Somehow the Titanic doesn't make the list, presumably because its compass wasn't at fault.

Devotees of sea stories will find this mildly interesting if ultimately repetitious, but supposedly "Compass" is about, well, compasses, which too often get lost in all the smashups. They also get lost in Gurney's well-intentioned but bumbled attempts to clarify the difficulties that had to be overcome before a reliable maritime compass could be developed and manufactured. What they boiled down to was the presence of iron aboard ship in places other than the needle of the compass, iron that became magnetized through natural processes and diverted the compass from true north. As one 18th-century shipman wrote:

"I am pretty well convinced that the quantity and vicinity of iron in most ships has an effect in attracting the needle; for it is found by experience that the needle will not always point in the same direction when placed in different parts of the ship; also it is rarely found that two ships steering the same course by their respective compasses will go exactly parallel to each other; yet these compasses, when compared on board the same ship, will agree exactly."

The problem proved to be more easily described than solved, a not uncommon occurrence in the history of science and technology. It's an interesting problem, and many interesting books have been written about it. "Compass" is not one of them.