No natural molecule on the planet is more fascinating thanwater. It has unique properties ranging from the unusualangles formed between its two hydrogen ions and its singleoxygen molecule, to the fact that unlike most substances, itexpands when it freezes rather than shrinks and reachesa maximum density as a liquid 4?F above its freezingpoint. These and many other aspects of the special physicsand chemistry are described in this volume, including theimpact of a wide variety of chemicals occurring in water,osmosis, diffusion, hydration, isotope exchange, along withthe fun physics of the mariotte bottle.Equally fascinating are the many unusual physical andchemical encounters in both the ocean and the atmosphere.Although oceanography and meteorology are frequentlyconsidered separate sciences from hydrology, their limitedinclusion in theWater Encyclopediawas deemed necessaryto tell the complete story. Tidal changes, benthic nutrients,the sea floor, el nino, sea level, and oceanclimaterelationships make up but a few of the oceans fascinatingstories, whereas water spouts, hurricanes, monsoons,droughts, sublimation, and barometric efficiency just touchthe tip of what this volume has in store in the area ofmeteorology.