This book comprehensively describes all aspects of gravity flow, a physical process in the environment that is covered by many disciplines including meteorology, oceanography, the earth sciences and industrial processes. The first edition was very well received, and the author has brought the new edition completely up to date, with much new material. Simpson describes gravity currents with a variety of laboratory experiments, many from his own work. Gravity Currents is a valuable supplementary textbook for undergraduates and a reference work for research workers. The general reader will also find much of interest, since the author clearly describes the physics of flows involved without advanced mathematics, and with numerous photographs and illustrations.

The sea breeze affects our lives in many ways. It controls our local weather, not only on the coast but also in many districts inland. Air pollution and smog, also the distribution of airborne insect pests and the spread of pollen are all controlled by the sea breeze. In the world of sport it is important to glider pilots, sailors and surfers, and balloonists. In the book we see how radar, lidar and satellite photography have helped to forecast and map sea breezes and the all-important 'sea-breeze front'. The book ends with a description of laboratory experiments mostly carried out by the author and his co-workers, and a simple summary of theoretical models. The book will be welcomed by those researching in the subject but will also be valuable to the general reader who is interested in local weather and the natural environment.

Referring to specific information inside an XML document is a little like finding a needle in a haystack. XPath and XPointer are two closely related languages that play a key role in XML processing by allowing developers to find these needles and manipulate embedded information. By the time you've finished XPath and XPointer, you'll know how to construct a full XPointer (one that uses an XPath location path to address document content) and completely understand both the XPath and XPointer features it uses.