Time is naturally marked by repeating astronomical phenomena, by the daily cycle and the seasons, as nights and months come and go. To slice it into finer fractions, our forbears invented sundials, which track the movement of the shadows projected by the sun, or clepsydra, hourglass-like devices that count time based on a consistent rate of water flow. But ever since 1657, when the first watch was created, we have used the oscillatory movements of a mechanical system to do that job. The photographer Guido Mocafico, whose previous books include "Venenum, Medusa" and "Serpens," sets out in this new project, "Movement," to observe these systems. He chose complex and rare mechanisms--physically mechanical rather than electronic--which led him into a world of traditional knowledge controlled by master watchmakers. To remove the back from one of their tiny creations is to plunge into an unknown world: these images of the tiny springs, levers, screws and gears that drive the hands of time forward, etched with the slightest texture possible and engraved in the smallest type possible, present an abiding mystery of the everyday, representative of all of the technologies we have come to take for granted. Mocafico was born in Switzerland in 1962. A specialist in still life, he works for international magazines such as "Vogue," French "Vogue, The Face" and "Wallpaper." Based in Paris, he has also undertaken numerous advertising campaigns for Gucci, Yves Saint Laurent, Clinique, Shiseido and Hermes.