Preface to Second Edition Several new topics have been added, some small errors have been corrected and some new references have been added in this edition. New topics include aberration corrected instruments, scanning confocal mode of operations, Bloch wave eigenvalue methods and parallel computing techniques. The ?rst edition - cluded a CD with computer programs, which is not included in this edition. - stead the associated programs will be available on an associated web site (currently people.ccmr.cornell.edu/ kirkland, but may move as time goes on). I wish to thank Mick Thomas for...