This slim book (only 120 pages, excluding the notes and index), sets out to present the history of one of the most important technological innovations ever created: the clock. Seemingly banal to us modern people, who have clocks and watches all around us - I have a watch on my wrist, a clock on my desk, and clocks visible on my computer screens, as well is in my car, and on various storefronts I pass - the timepiece revolutionized the world, allowing events to occur at pre-determined moments, and allowing people to organize their labor and lives in a different way. While we are often at the mercy of the clock, running for that train, trying to be on-time for that meeting, or waiting for the dentist who is late, no other invention has changed the world so profoundly.

This book begins with a prologue that sets out the context in which the clock was invented. After the "renaissance" of the 12th century in Europe, when population grew rapidly, technology was mastered, and craftsmen became key players in society, the book examines the crucial period between 1300 and 1700, when the clock was refined and democratized. (Curiously, Cipolla does not explain exactly why such a renaissance occurred in the 12 century, and seems almost perplexed. This book was originally published in 1967, at which time historians were not aware that the 12th century was a period when the climate in Europe became much warmer than in previous centuries. The climate had cooled considerably during the "dark ages", making it more difficult to eke out a living from the soil. When the climate warmed in the 12 century, food was suddenly abundant, leading to an increase in population and the ensuing changes in societal structure.)

Mankind had always attempted to measure time precisely; as early as antiquity , using sundials, then later with clepsydra, or water clocks. But not until the late thirteenth century were clocks finally created that approached a level of accuracy that would change the world. This occurred when the verge escapement with foliot was invented: this mechanism was the heart of the early mechanical clock.

During the 14th century, clocks become more numerous in Europe, essentially in churches, cathedrals and monasteries, for it was here that time was most important. Some of these clocks could chime out the hours, allowing for more precise times for religious services. Clocks were expensive, but during this century and the next, many towns and cities began commissioning clocks, out of both civic pride and economic hope - the clocks could help bring more merchants to fairs, and citizens would lead more orderly lives.

Like much technology, these mechanical timepieces began as public objects and slowly found their way into the home; first the homes of the rich, but, beginning in the 16th century, more clocks and watches appeared in the homes of the middle-class. In the 17th and 18th centuries, the rise of "science" as a true métier, and a search for precision in all aspects of technology, led to improvements in accuracy. No longer were clocks merely designed to tell the hour and the minute, but accuracy to the second was the new goal. This was not born out of any desire to know the precise time to the second, but rather to ensure that clocks remained accurate over time. A clock that lost 10 seconds a day would lose more than a minute a week, and would soon stray from the actual time.

Cipolla only examines the growth in the clockmaking industry without looking into the profound effects that taming time had on mankind. Other than a brief mention in the epilogue, where he talks about how hours of equal length were adopted across Europe, does he raise the questions of the effect that this new common time had on both trade and technology. Longitude would never have been discovered without accurate clocks. The railroad could not have functioned without synchronized clocks, and telegrams would have been more difficult to send across the Atlantic without an awareness of times and time zones. When mankind adopted precise time, it enabled laborers to be paid for the hours they worked, and not the days; it allowed meetings to be scheduled at precise times; it permitted transportation to leave and arrive at predetermined times.

This book is not meant to examine how time revolutionized the world, but even in the period it covers, Cipolla should have delved into the societal changes that this technology engendered. While this is an interesting examination of the technology itself, it does not explore the effect of that technology on the world around it, and ultimately disappoints for that reason.

Kirk McElhearn

Kirk McElhearn (kirk@mcelhearn.com) is a freelance writer and translator living in a village in the French Alps. You can find out all about him at his web site, http://www.mcelhearn.com.