

An analemma is the figureofeight shape that results if the Sun's position in the sky is recorded at the same time of day throughout the year. The gnomon of a sundial draws a similar figure. 







Make your own sundial just by folding a
sheet of paper. 



4.
Cylinder Sundial 
Java applet drawing a cylinder sundial indicating clock time.  
5. Sundial Box 
Java applet drawing an
hour scale for a Compact Disk. 



6. Spider Sundial  A horizontal sundial using a vertical gnomon. It depends on the azimuth angle of the Sun.  


7.
Spider: Vertical and Polar Pointing Gnomon 
A horizontal sundial using a vertical gnomon. It depends on the azimuth angle of the Sun.  


8. North Finder  This horizontal sundial combines two different principles and is selfaligning to true north.  


9. Bifilar Sundial  This sundial
uses two nonintersecting threads parallel to the
horizontal dial plane. The upper thread (distance a
above the plane) is oriented NorthSouth, the lower
(distance b) is orthogonal to the first. The
intersection of the two threads' shadows gives the
time. 



10. Cone Sundial  This sundial
uses a horizontal gnomon. The hour lines and the date
lines are drawn on to a cone. 



11. Babylonian, Italian, Unequal Hours Sundial  The Babylonian
system divides the day into 24 equally long hours
beginning at sunrise and ending with the following
sunrise. Italian hours begin counting at sunset and ends 24 hours later with the following sunset. 



12. Pingre Sundial  This unique
sundial was invented and designed by the French
astronomer Alexandre Guy Pingré (1711  1796). It is similar to the cylinder sundial, but there are multiple gnomons in a horizontal plane, perpendicular to the cylinder. 



13. Daylight Hours Sundial  The gnomon of
this sundial is vertical. The shadow of it's top on
the horizontal plane is used to read the sundial. The declination lines are computed for full numbers of daylight hours which depend on the latitude of the observer and the declination of the Sun. 



14. Sidereal Time Sundial  This horizontal sundial is showing the local sidereal time, which is defined as the hour angle of the vernal equinox.  


15. FosterLambert Sundial  The gnomon produces a circular ring of equiangular hour points.  


16.
Azimuthal Orthographic Sundial 
Azimuthal Sundial for both
solar and standard time. 



17. Gnomon  This type of
sundial has a vertical gnomon casting the shadow on a horizontal plane. 

Additional Applets: 

Sun: Declination, Equation of Time, Transit Time 
Tables, and diagrams. 



The applets computes the times of sunrise and sunset, and more astronomical data, which are updated every second. 



The applet displays the times of sunrise and sunset. 

Equation of Time 

The applet displays the current declination of the sun and the equation of time. 

& Equation of Time 

The applet displays the current declination of the sun and the equation of time. 



You may edit the applet parameters for your location and the number of lines. 



You may edit the applet parameters for your location and the number of lines. 



SunClock  


Twilight Clock  
Spider Sundial 

On my Home Page: Astronomie by JavaScript Home Page: http://www.jgiesen.de Last Modified: 2012, May 12 