Get Lee Valley Tools - Sundial

And although no one knows for certain who actually invented the sundial, its credit goes mainly to the ancient Egyptians who, by 1500 BC, had perfected the “shadow clock,” a more portable device that measured time throughout the day.

In the history of sundials, the oldest sundial devices came from the ancient Egyptian shadow clock built around 1500BCE. The obelisks shadow clocks were created in an L shape and placed east to west amongst the cardinal points.

High up on Muottas Muragl (2,456 m), on a spot just above the Romantik Hotel Muottas Muragl, is SINE SOLE SILEO, the most accurate sundial in the world! In summer, it functions as a sundial, and in winter, as an almost equally precise moondial.

0:28 2:29 Setup a Sundial - YouTube YouTube Start of suggested clip End of suggested clip The shadow will change and indicate the time. This next sequence shows the shadow moving from 2 p.m.MoreThe shadow will change and indicate the time. This next sequence shows the shadow moving from 2 p.m. to 6 p.m. as the Earth turns we can watch as the shadow progresses.

The oldest known sundial was made in Egypt in 1500 BC. It was L-shaped. The top of its vertical leg cast its shadow on the horizontal leg. The shadow's length, not its location, roughly indicated the time.

By the 8th century bce more-precise devices were in use. The earliest known sundial still preserved is an Egyptian shadow clock of green schist dating at least from this period. The shadow clock consists of a straight base with a raised crosspiece at one end.

The gnomon of the vertical sundial makes an angle of 90°–L with the vertical (that is, an angle L with the horizontal), as shown in the side view in Figure 5. In the southern hemisphere, the vertical dial is north-facing.