Sundials

Sundials are perhaps the most ancient of scientific instruments, and the earliest known form of time-keeping. They probably started life as poles in the ground with the direction and length of the shadow giving an approximate time of day. However, by the middle of the second millennium BC there were already fixed and portable versions of more accurate sundials being produced in the Middle East, Egypt and China. These early sundials relied on the height of the sun in the sky to indicate the time by the length of the shadow it produced.

http://www.hps.cam.ac.uk/starry/sundials.html

 

http://plus.maths.org/issue11/features/sundials/

Analemmatic sundials: How to build one and why they work

http://www.adonisgarden.com/buy/decor/sundials.htm

http://www.ubr.com/clocks/sundial/sundial.html

http://web.fc-net.fr/frb/sundials/gb/defaut.htm

http://www.factmonster.com/ipka/A0855486.html

http://home.iae.nl/users/ferdv/compute.htm

A UNIFORM METHOD TO COMPUTE FLAT SUNDIALS

http://www.courtyardsundials.co.uk/

COURTYARD SUNDIALS

http://www.hps.cam.ac.uk/starry/sundcalen.html

Sundials and Calendar Reform

http://www.danieloberti.com/sundials.html

http://www.ghh.com/sundials/sundials.html

http://solar.physics.montana.edu/YPOP/Classroom/Lessons/Sundials/sundials.html

Sunshine in your pocket! Making a sundial for the Northern hemisphere.

http://liftoff.msfc.nasa.gov/academy/Earth/Sundial/Sundial-how.html

How Sundials Work

http://www.sundials.co.uk/

Sundials on the Internet

http://www.sundials.co.uk/projects.htm

http://www.stedmunds.co.uk/lifestyle/manor/port-sun.html

Portable Sundials

http://sundials.org/links/

http://www.cpcug.org/user/jaubert/jsundial.html

http://users.argonet.co.uk/education/sunclocks/

'Human  Sundial'

http://www.spot-on-sundials.com/

The Spot-On Sundial

http://www.math.sfu.ca/histmath/Special/Introduction.htm

Welcome to the Development of Sundials