1. Review of ZrO/W schottky cathode / Lyn W. Swanson and Gregory A. Schwind -- 2. Liquid metal ion sources / Richard G. Forbes and (the late) Graeme L.R. Mair -- 3. Gas field ionization sources / Richard G. Forbes -- 4. Magnetic lenses for electron microscopy / Katsushige Tsuno -- 5. Electrostatic lenses / Bohumila Lencov ̀-- 6. Aberrations / Peter W. Hawkes -- 7. Space charge and statistical coulomb effects / Pieter Kruit and Guus H. Jansen -- 8. Resolution / Mitsugu Sato -- 9. The scanning electron microscope / Andrs̀ E. Vladr̀ and Michael T. Postek -- 10. The scanning transmission electron microscope / Albert V. Crewe (updated by Peter D. Nellist) -- 11. Focused ion beams / M. Utlaut -- 12. Aberration correction in electron microscopy / Ondrej L. Krivanek, Niklas Dellby, and Matthew F. Murfitt.