Many people have seen the old sundial which still sits in close proximity to where the first Huletts hotel stood. To the best of my knowledge, it still keeps pretty accurate time. As the summer draws to a close, I thought this might make an interesting post.
Wikipedia has a long description about sundials here but I present the “short version” below.
A sundial is a device that measures time by the position of the Sun. In the most common design, the sun casts a shadow from its Gnomon, a thin, straight edge onto a flat surface marked with lines indicating the hours of the day. As the sun moves across the sky, the shadow-edge progressively aligns with different hour-lines. Such designs rely on the Gnomon being aligned with the axis of the Earth’s rotation. For a sundial to work correctly in the northern hemisphere, the Gnomon must point towards true north (not the north magnetic pole) and the Gnomon’s angle with horizontal must equal the sundial’s geographical latitude. Huletts Landing’s latitude is 43.6392326355 degrees.
The shadow-casting Gnomon must be in a fixed position and aligned with the Earth’s rotational axis. It must be oriented with true North, making an angle with the horizontal equal to the sundial’s geographical latitude. This axis can only be aligned with the celestial north pole, which is closely aligned with the (present) North star, Polaris. In other words, it can’t be positioned with a compass, it must be positioned with the North star.
If the shadow-casting gnomon is aligned with the celestial north pole, its shadow will revolve at a constant rate, and this rotation will not change with the seasons. That’s why a sundial works through all seasons of the year.
So while I don’t know the year the sundial was put in place, I can say with some certainty that it was positioned at night and those putting it into place stopped and found the North star. Our proof is that it still works today.
So as Labor Day brings this summer to a close, have a great break and a good rest.