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How to Make Simple Sun Dials

The common clock that we know today wasn't accurate until the early 20th century. In the past, clocks were constantly being corrected by sundials, a simple device for telling time used by many ancient cultures for thousands of years. The Egyptian obelisk is probably the most common and simple of all archaic sundials, though it's not exactly accurate. Modern sundials, however, are based on latitude and mathematical algorithms to enhance their accuracy. Basic sundial technology is simple and effective, and a sundial is easy to make.

Things You'll Need

Wood or cardboard
Glue or tape
Pen and pencil
Sundial latitude blueprint
Compass

Instructions

- 1
  Cut a base for the sundial out of cardboard or wood in the shape of a circle no more than 8 inches in diameter. Mark the center of the base with a pen.
- 2
  Find a straight object such as a stick or pencil to use for the gnomon---or pointer---of the sundial. This is the piece that will cast the shadow onto your sundial.
- 3
  Find your latitude on a detailed map or do an Internet search to calculate your latitude. From there, find a sundial face blueprint or pattern in your library or online. The blueprint or pattern will be accompanied by instructions about how to alter or fold for latitude; follow these instructions according to your latitude and fold it accordingly.
- 4
  Place the sundial pattern on your base, then transfer the lines from the pattern onto it, labeling each line with the corresponding hour. Ensure accuracy with this step or the sundial will not be effective.
- 5
  Attach the gnomon (stick or pencil), ensuring that it's adjacent to the north/south line on the base. Tape or glue the gnomon into position to ensure accuracy, then calculate a true north position with a compass and point the gnomon northward as read on the compass. The shadow then should be cast on the appropriate time of your sundial.

Astronomy