How to Make a Telescope

	How to make a telescope by Jean Texereau 424 pages Level: Technical A complete and detailed description on how to build a telescope from scratch by one of the leaders In the field.

I purchased my copy of "How to Make a Telescope" after being frustrated by the lack of light gathering power of my 4 1/2 inch store bought reflector. As I quickly discovered, grinding one's own mirror and then building a telescope to house it was way beyond my limited ability. I'm the type of person who avoids hanging pictures on the wall, because the operation necessitates hammering a nail straight. The many operations needed to build a telescope are considerably more complex than that. So I can give you a general impression of Texereau's book, but must admit that I haven't tried it myself. "How To Make A Telescope" starts off with a Newtonian 8 inch reflector with a focal length of f/6 or f/8 on an azimuth mounting. If none of the previous sentence makes any sense to you, start off with a more elementary that will introduce you to the subject of telescopes in a more gentle manner. Texereau provides extremely detailed instructions for the many steps necessary to construct a telescope and its mirror from scratch. Not only are instructions provided on grinding the mirror and building the rest of the instrument, but the equally important stage of adjusting and testing the newly made telescope is not neglected either. Besides the "standard" Newtonian, there are sections for more complex projects such as a Cassegrainian telescope and an equatorial mounting. Among the many useful appendices there is one on suppliers to help the reader purchase the necessary materials.
Review by Ed Ehrlich

Table Of Contents
Preface Acknowledgments Foreword to the Second English Edition, Richard Berry Foreword to the First English Addition, Albert G. Ingalls Foreword to the 1951 French Edition, Andre Couder Preface I. Basic Principles And A proposed Telescope I-1. "Geometric Optics" and the Astronomical Telescope I-2. A bit of Physical Optics I-3. Definition of a Perfect Objective I-4. The Rayleigh Criterion I-5. Principal Types of Telescopes I-6. Refractor vs. Reflector as the Amateur's Telescope I-7. Practical Conclusion: The "Standard" Telescope II. Making The Main Mirror II-1. Form of the Main Mirror in the Newtonian Telescope II-2. Working of Optical Surfaces and Theories concerning Polishing II-3. The Mirror Blank and tool II-4. Abrasives II-5. Polishing Materials II-6. Summary of Grinding and polishing Needs II-7. Work Support and Accessories II-8. Preparing the Mirror Disk II-9. Rough Grinding II-10. Testing Radius of Curvature II-11. Finishing rough Grinding II-12. Fine Grinding and Smoothing II-13. Characteristic of the Smoothed Optical Surface II-14. Pitfalls in the Smoothing Operation II-15. The Polishing Lap II-16. Making the Lap II-17. Polishing conditions and Requirements II-18. The Polishing Operation II-19. Completion of Polishing II-20. Surface, Wavefront, and Image Errors II-21. Review of Possible Test Methods II-22. Nature of the Foucault Test II-23. Foucault Test Apparatus II-24. Making the Foucault Test II-25. Diffraction Effects in the Foucault Test II-26. Sensitivity of the Foucault Test II-27. Principle of Parabolic Mirror Testing II-28. Definitions Relating to Spherical Aberration II-29. Effects of Spherical Aberration II-30. Measurement of Spherical Aberration II-31. The Couder Screen II-32. Screen Test Procedure; Errors II-33. Defects Other than Figures of Revolution II-34. Primary and Micro-Ripple II-35. Zonal Defects II-36. Local Retouching II-37. Parabolizing II-38. Retouching the Defective Parabola II-39. Reducing Aberrations to the Focal Plane II-40. Test Data Sheet II-41. Interpreting the Test Data III. The Plane Diagonal Mirror III-1. Mirror vs. Prism-Comparative Requirements III-2. Form and Dimensions of the Diagonal Mirror III-3. Interference Test for Flat Mirrors III-4. Making the Interference Test III-5. Testing by Combination with a Spherical Mirror III-6. The Diagonal Mirror Blank III-7. Resurfacing the Flat Mirror III-8. Cutting the Mirror IV. Mechanical Structure IV-1. Choice of a Standard Design IV-2. Important Details V. The Azimuth Mounting V-1. Principles of Design V-2. Details of Importance or Interest VI. Making A Cassegrainian Telescope VI-1. The Classic Cassegrainian: Configuration and Notation VI-2. Advantages and Disadvantages of the Classic Cassegrainian VI-3. The Coude or Nasmyth Modifications VI-4. Selection of Design Constants VI-5. Calculating Related Design Constants VI-6. Deformation Coefficients and Off-Axis Aberrations VI-7. Judging the Difficult of Figuring VI-8. Design Examples for Two Cassegrainian Telescopes VII. Making The Primary Cassegrainian Mirror VII-1. Rough Check for Strain VII-2. Cutting the Hole VII-3. Finishing the Perforated Mirror VII-4. The Apertured Couder Screen VII-5. Parabolizing Mirrors of Large Relative Aperture VIII. Making The Secondary Cassegrainian Mirror VIII-1. Testing Combined Mirrors on a Star VIII-2. Testing the Combined Mirror with a Plane Mirror VIII-3. Method of Hindle VIII-4. Testing the Secondary Against a Concave Reference VIII-5. General Procedure for Small Mirrors VIII-6. Edging VIII-7. Rough Grinding VIII-8. Spherometry VIII-9. Smoothing VIII-10. Polishing and Retouching IIX. Mechanical Design Of The Cassegrainian IIX-1. Adaptation of the Standard Telescope Tube IX-2. Cylindrical Tubes IX-3. Construction of a 257 MM Cassegrainian X. The Telescope Window X-1. Advantages of a Telescope Window X-2. Choice of Glass X-3. Cutting the Central Hole and Edging X-4. Smoothing Tolerances and Parallelism X-5. Rough Grinding, Fine Grinding and Smoothing X-6. Optical Testing of the Window X-7. Polishing and Retouching X-8. Quantitative Testing and Data Reduction XI. The Eyepiece XI-1. Role of the Eyepiece and Its Selection XI-2. Principal Types of Eyepieces XI-3. The Barlow Lens XI-4. Standard Series of Plossl Eyepieces XII. The Equatorial Mounting XII-1. General Discussion XII-2. Principle Types o Equatorial Mountings XII-3. Designs to be Avoided XII-4. Practical Advice for Construction of a Cradle Mounting XII-5. Practical Advice on Offset Cradle Mountings XII-6. Practical Advice on Simple English Mountings XII-7. Practical Advice on German Mountings XII-8. Practical Advice on Fork Mountings XII-9. Practical Advice on Mountings with a Table Atop the Polar Axis or Inverted Fork XII-10. Generalizations Concerning Clock Drives XII-11. Drive Using a Screw and Smooth Sector XII-12. Classic Drive Using Worm and Wheel Combination XIII. Accessories, Mirror Coating, Paint And Metal Part Finishing XIII-1. Finders XIII-2. Photographic Plate Holder and Lateral Eyepiece XIII-3. Paints and Metal Part Treatment XIII-4. Reflective Mirror Coatings XIII-5. Chemical Silvering XIII-6. Alumnizing XIII-7. Shipping the Mirror for Aluminizing XIII-8. Care of Aluminized Mirror XIV. Adjustment of Mirrors And Mountings XIV-1. Aligning the Mirrors XIV-2. Aligning the Cassegrainian XIV-3. Balancing the Equatorial XIV-4. Siting of the Equatorial Telescope XV Atmospheric Turbulence XV_1. Difficulties in the Use of a Medium-Power Telescope XV-2. Atmospheric Defects XV-3. Star Image Changes in the Small Instrument XV-4. Star Image Changes in a Large Instrument XV-5. Image Changes Due to Photographic Diffusion XV-6. First Stage of Turbulence: The Instrument XV-7. Second Stage: Local Turbulence XV-8. Third Stage: High-Altitude Turbulence XV-9. Conclusion Appendix A. List of Suppliers B. Data Reduction Computer Programs in Basic For Mirrors and Windows C. Two-Mirror Telescope Computer Program in BASIC D. "Gleamings for ATM's" From Sky and Telescope Magazine, November 1941-December 1983 E. Bibliography of Telescope Making Magazine, Volumes 1 Through 20 F. Index to Selected Telescope Making Articles in Scientific America 1925-1959 G. Exact Formulae for Calculating Size and Offset for Newtonian Diagonal Mirrors H. Electronic Drive Controls for Declination and Right Ascension Axes I. The Dobsonian and Poncet Mount Adapted to the Texereau Standard Telescope J. Pitch Testing K. Unusual Amateur Telescopes L. A Short Biography of the Professional Work of Jean Texereau Bibliography Index

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