created by Carl Sabanski
Make a Sundial - Graphical Method - More Hour Lines
Did you think about it?
Take a look at Figure1. This is the horizontal sundial that you worked on. The technique would be same for a vertical sundial. At the top is the original equatorial sundial that was used to find the hour lines of the sundial. Below it is a scaled down version of the equatorial sundial that is drawn following the same steps used for the larger one. But because it is smaller additional hour lines can now be added earlier and later in the day. The important fact to note is that both equatorial sundials are drawn relative to the same point C. This point is the centre of the sundial you are drawing, in this case a horizontal sundial, and all the hour lines originate from this point. That is why the full hour line points that you see in Figure 1 for both equatorial sundials fall on the same hour lines. This will be true for any hour lines you draw.
Figure 1: Adding More Hour Lines (CAD)