The Design and Construction of Large Optical Telescopes Astronomical Observations Instruments Design Methods and Project Management Telescope Optics Stray Light Control Telescope Structure and Mechanisms Pointing and Control Active and Adaptive Optics Thermal Control Integration and Verification Observatory Enclosure Observatory Sites. There is no dearth of books on telescope optics and indeed optics is clearly a keyelementinthedesignandconstructionoftelescopes.Butitisbynomeans the only important element. As telescopes become larger and more costly other aspects such as structures pointing wavefront control enclosures and project management become just as critical. Although most of the technical knowledge required for all these elds is available in various specialized books journal articles and technical reports they are not necessarily written with application to telescopes in mind. This bookisarstattemptatassemblinginasingletextthebasicastronomicaland engineering principles used in the design and construction of large telescopes. Itsaimistobroadlycoverallmajoraspectsoftheeld fromthefundamentals ofastronomicalobservationto optics controlsystems structural mechanical andthermalengineering aswellasspecializedtopicssuchassiteselectionand program management. This subject is so vast that an in depth treatment is obviously imprac cal. Our intent is therefore only to provide a comprehensive introduction to the essential aspects of telescope design and construction. This book will not replace specialized scientic and technical texts. But we hope that it will be useful for astronomers managers and systems engineers who seek a basic understanding of the underlying principles of telescope making and for s cialists who wish to acquaint themselves with the fundamental requirements and approaches of their colleagues in other disciplines.