*Cover photo* : Roman engineers of Antiquity built highly developed water supply systems. The Pont du Gard (c. 19 BC) in southern France, below, is only a small section of a 40-kilometre-long conduit, mostly underground, which carried water to the city of Nimes. Its 3 tiers of arches rise to over 47 metres. The highest tier, carrying the conduit, consists of 35 4.6-metre arches."

INTRODUCTION

Alain GIODA
Hydrologist, ORSTOM (Institut français de recherche scientifique pour le développement en coopération) and SENAMHI (Servicio Nacional de Meteorolgía e Hidrología)br> Casilla 2352,
Cochabamba, Bolivia
Tel.: (591-42) 47033,
Fax: (591-42) 56321,
e-mail: gioda@bo.net

This article is dedicated to the memory of two European botanists who took a keen interest in the history of science and the flora of Latin America: Dr Marcel Kroenlein, director for many years of Monaco's Jardin Exotique; and Pierre Fontanel, a young engineer from Montpellier specializing in weeds

After a historical evocation of the concept of the water cycle, water is presented in its various aspects: as friend and foe of humankind, a source of power, an apple of discord, a common heritage and a victim. The purpose is to illustrate in a historical and global context the diversity, and hence wealth, of the connections between people and water.