Table of Contents

I THE DEVELOPMENT OF THE SUNDIAL A brief outline from ancient times to the present. II WHY THE SUNDIAL TELLS TIME What you ought to know. Invention of the armillary and its use. Mean Time and Standard Time. III HOW TO DESIGN AND MAKE A DIAL Simple instructions how to go about making a sundial. IV SELECTING THE DIAL TO MAKE OR BUY: GUIDELINES AND MATERIALS What to look for when buying a dial. Notes concerning individual dials and suggested locations or settings to aid in selecting the type of dial best suited to your needs. Various materials commonly used in making dials. Classification of dials. V PARTS OF A DIAL YOU SHOULD KNOW Descriptions of terms and parts commonly associated with sundials. How to determine a true north line or meridian. How to find the declination of a plane or dial. How to find the reclination of a plane or dial. How to set your dial. How to make and use a vernier. VI TIME AND STANDARD TIME DIALS How time is obtained. The equation of time explained and its use. How Standard Time may be obtained from the reading of a sundial. How to make Standard Time Dials. The heliochronometer. VII HOW TO LAY OUT THE HOUR LINES The graphic method of laying out hour lines on many types of dials. Hour limitations of the various dials. Setting the dials. VIII DIAL FURNITURE "Description and use of various lines, figures and symbols which may be added to the dial that it may be of more interest and use." Educational value of the sundial and its furniture. The signs of the Zodiac defined. IX HOW TO LAY OUT THE LINES OF DECLINATION The graphic method of laying out the lines of declination on many types of dials. X PORTABLE SUNDIALS "Types of Azimuth and Altitude Dials: Ring, Cylinder, Quadrant, Capuchin, O-G, Horizontal Altitude, Horizontal Azimuth, Magnetic Azimuth. " XI VARIABLE CENTER DIALS Analemmatic and Lambert Dials. XII THE HELIOCHRONOMETER Details and construction. The Analemma. How to use the Heliochronometer. Formulae for the Analemma. XIII SUNDIAL CLASSIFICATION Oridinary and Special Types. Definitions and criteria for distinguishing various kinds. Classification scheme and register card. XIV INTERESTING DIALS OF THE WORLD The Great Dial at Jaipur A Desirable Instrument A Noon Mark Goes to Sea An Armillary The Whitehall Dial Flower Time A Moon Dial Cathedral Dials Singing Tower Dial Exploration And Fired the Shot Heard at Noon. XV HUNTING SUNDIALS Where to look for dials and how to photograph them. APPENDIX I FORMULAS "Formulas for computing the position of the hour lines on many types of dials, by trigonometry." The tangent method of laying out the hour lines. How to compute the azimuth and altitude of the sun. Computing the azimuth and time of sunrise and sunset. II TABLE FOR CONVERTING DEGREES OF ARC INTO MINUTES OF TIME OR VICE VERSA A convenient table to relieve you of a laborious calculation.