Have you every wanted to build a sundial or to understand how one works? Then you have probably been frustrated as you search vainly for help. Most books on the subject are either rare out-of-print works published centuries ago and available only in highly specialized collections, or highly complicated treatises whose information is hidden behind frightening arrays of involved formulas. But now your search is over. This book is designed to meet sundialing needs at either the simple or the sophisticated level.
Albert E. Waugh, professor and administrator at the University of Connecticut for 40 years, and an expert on the subject of sundials and their curious history, presents, on the one hand, a rigorous appraisal of the science of sundials, including mathematical treatment and an explanation of the pertinent astronomical background; on the other hand, he presents simple and non-technical treatments such that several of the dials can be built by children!
The subject matter is arranged in 19 chapters, each covering a different aspect of dialing science. All the common types of dials are covered, but the reader can also learn about analemmatic dials, polar dials, equatorial dials, portable dials, memorial dials, armillary spheres, reflected ceiling dials, cross dials, and old-fashioned noon marks. There are also sections on dial furniture, mottoes, the actual layout out of a dial, the equation of time, finding time in other cities, how to find the meridian, how to find time by moonlight — even how to estimate time from the length of one’s own shadow! Directions are given for designing dials for any part of the country, or any place in the world. The author has designed many dials, and his text is filled with helpful hints based on his own personal experience. There are over 100 illustrations, charts, and tables, followed by an appendix which is filled with material which reduces or eliminates the need for calculation on the part of the reader.
Inhaltsverzeichnis
1. Historical Sketch2. Kinds of Time
The Sun’s Apparent Motion.
Differences in Longitiude.
Local Apparent Time.
Local Mean Time.
The Equation of Time.
Converting from Apparent to Mean Time.
Standard Time.
Longitude Corrections.
Conversions from Standard Time to Local Apparent Time.
Time When the Sun Souths.
Daylight Saving Time.
3. The Noon Mark
Finding the Meridian.
The Analemma.
Finding the Analemma by Computation.
4. The Equatorial Sundial
Showing Standard Time.
5. The Horizontal Sundial
General Appearance of the Horizontal Dial.
The Latitude.
Laying Out the Hour Lines Graphically.
Laying Out the Hour Lines in a Unit Square.
Laying Out the Hour Lines with Tabulated Angles.
Laying Out the Hour Lines by Computation.
Longitude Correction for Horizontal Dials.
Adjustment to New Latitudes.
Limiting Hour Lines.
6. Vertical Direct South Dials
7. The Vertical Direct North Dial
8. Vertical Direct East and West Dials
Direct East and West Dials by Calculation.
9. The Polar Dial
Graphic Construction.
Construction by Calculation.
10. Vertical Declining Dials
Graphical Method.
The Computational Method.
What Hour Lines to Include.
Vertical North Decliners.
Limiting Hours on North Decliners.
Measuring a Wall’s Declination.
An Alternative Method of Finding a Wall’s Declination.
Dials with Large Declination.
11. Direct Reclining or Inclining Dials
Direct South or North Recliners or Incliners.
Direct East or West Recliners and Incliners.
12. Dials Which Both Decline and Recline
13. The Analemmatic Dial
Laying Out the Hour Points.
Finding the Hour Points from Central Angles.
General Observations.
14. Reflected Ceiling Dials
Drawing Hour Lines by Observation.
Drawing the Dial by Computation.
15. Dial Furniture
Dial Mottoes.
The Equation of Time.
Showing the Time in Other Cities.
The Nodus and the Perpendicular Style.
The Sun’s Azimuth.
The Sun’s Altitude.
Lines of Declination.
The Use of Tables.
Graphic Approach.
Vertical Direct South Dials.
Polar Dials and Vertical Direct East or West Dials.
Lines of Declination: Vertical Declining Dials.
The Length of Day.
Signs of the Zodiac.
16. Portable Dials
The Shepherds’s Dial.
Graphic Approach.
Arithmetic Approach.
Tablet Dials.
Cubic Dials.
Portable Cross Dials.
Pocket Equatorial Dials.
The Universal Ring Dial.
Perforated Ring Dials.
The Sun Watch.
The Capuchin Dial.
A Very Early Portable Dial.
Time-Telling at Night.
Time by Moonlight.
The Nocturnal.
17. The Armillary Sphere
Methods of Measurement.
Laying out the Rings.
The Sun’s Declination.
18. Memorial Dials
Headstone with a Sloping Surface.
The Cross Dial.
Star of David Dials.
19. Practical Hints on Dialling
Laying out an Ellipse.
Setting the Dial in Place.
Finding Latitude and Longitude.
Appendix
Table A.1 The Equation of Time.
Table A.2 Declinations of the Sun.
Table A.3 The Zodiac.
Table A.4 Conversion of Arc to Time.
Table A.5 Conversion of Time to Arc.
‚Table A.6 Latitudes, Longitudes and Standard Time Zones.‘
Table A.7 Earliest Sunrise and Latest Sunset.
Table A.8 Sunset Times at Various Latitudes and Seasons.
Table A.9 Data for Laying Out Dials in a Unit Square.
Table A.10 Hour Angles for Horizontal and Vertical Direct South Dials.
Table A.11 Factor Table for Reflected Ceiling Dials.
Table A.12 Factor Table for Finding Distances of Hour Lines from the Equinoctial on Reflected Ceiling Dials.
Bibliography
Index
Ebooks vom selben Autor / Herausgeber
11.369 Ebooks in dieser Kategorie
