How do I find North?
Using a magnetic compass, roughly layout the sundial using the dimensions provided. Use a garden hose as the ellipse. A compass only shows magnetic north and this isn’t accurate enough to construct the sundial. However, it is close enough for the preliminary layout and to find true north by using the solar method.
After the initial layout, we must accurately find the true north/south line. In the center of the oval, place two chairs back to back with a broomstick suspended across. The stick needs to be securely fastened to the chairs with strapping tape to prevent movement. From the stick we hang a plumb bob.
We want to find the shadow that the string line gives off. The shadow will be very clear as it gets lower to the ground. However, higher up the string will become blurry as the shadow becomes out of focus.
To assist in making the shadow clear at the higher level, tape a piece of cardboard that’s cut in a diamond shape. This assist in finding the shadow.
Tape a piece of paper on the concrete and mark an X at the point of the plumb bob.
We then need to find out what time the shadow will show us where the north/south line is. To do so, consult the table that is provided with your sundial. Like the sundial, it is area pacific and is calculated for longitude of your location.
In this example, we are construction the sundial on 5th March. We then look up the table and find that at 11:55 and 53 seconds, the shadow of the string will show us the true north/south line.
At 11:55:53 put an X on paper to mark the shadow. The north/south line runs along the two X’s that we drew.
From there, we place a string to show the north/south line. After that, we mark NS1 and NS2. The string line can be held in place and stretched by two bricks (not pictured)