'The work is undeniably of high scholarship, consummate accuracy and penetrating insight ... All specialists in stability theory will be happy that two such authorities have found the time, and spared so few pains, to produce a work of such excellence.' Nature '... continues to be ... essential reading in hydrodynamic stability, in particular for the novice. ... detailed solutions to many problems [are] given at the end of each section.' Zentralblatt MATH