The goal of this text is to present some of the basic ideas of fluid
mechanics in a mathematically attractive manner, to present the physical
background and motivation for some constructions that have been used in
recent mathematical and numerical work on the Navier- Stokes equations
and on hyperbolic systems, and to interest some of the students in this
beautiful and difficult subject. The third edition has incorporated a
number of updates and revisions, but the spirit and scope of the
original book are unaltered.