Build a Sundial and Join the Worldwide EarthDial Project
The EarthDial project links Webcam images of similar sundials built by schools, organizations, and individuals around the world. These Webcam images will then be linked to the Planetary Society Web site, where one will be able to view, in almost real time, sundials from around the world in all of the different time zones! As the eye sweeps across the images on this Web page, the Sun’s shadow will sweep across the faces of the dials. Web site viewers will gain a palpable sense of how the Sun illuminates the round globe that is our Earth.
Sullivan, W. 2003, Astronomy Education Review, 2(2), p.202–204