Annalemna

What the heck is an analemna? Is that the name of a new BCSIS kindergartener? Just kidding.

The lopsided figure 8 that you see at the bottom of the sundial, in the black non-shadowed area, is called an Analemna. It is a representation of the path of the sun throughout the year.

If you could record the position of the sun in the sky at the same time every day, you would notice that the sun takes a rather strange path. You might notice that at certain times throughout the year the sun's position not only varies higher and lower (North and South) as you would expect with the change of the seasons, but also slightly east and west. This figure-8 path that the sun makes in the sky is called the analemma. In the movie "Castaway", Tom Hank's character marks an analemna on the wall of his cave, and uses it to calculate the bast time to attempt an escape from the island.
For more information, and in-depth explanation, and some mathematical fun, see http://www.analemma.com/Pages/framesPage.html