Capricorn: Dec.22-Jan.29 The Sundial Primer
created by Carl Sabanski
Capricorn: Dec.22-Jan.29

Mr. Sun The Sundial Primer Index "Sunny Day U" Index Mr. Sun

"SUNNY DAY U"


Horizontal/Analemmatic Sundials Kit

Horizontal Sundial: the common or garden sundial with a horizontal dial plate and polar-pointing gnomon.

Analemmatic Sundial: sundials consisting of hour points (rather than hour lines) laid round an ellipse, and a movable gnomon perpendicular to the dial plane. It may be on any plane, but the most usual form is horizontal. In the horizontal version of the dial, gnomon position lies on the straight North-South minor axis, at a point determined by the sun's declination (i.e. the date). The analemmatic dial may be regarded as a projection of the universal equatorial ring dial.


The combination horizontal and analemmatic sundial presented here is a very useful sundial. The sundial is self orientating and can be used to find the true north-south line. This is done very easily by turning the dial plate until both sundials read the same time. Now you can align your other sundial models! 

Figure 1 shows the Kit that you will use to make your own combination horizontal/analemmatic sundial. The dial plate of this sundial is designed to fit on an 8-1/2" by 11" sheet of paper.  It is purposely made as a large as possible so the hour lines and points can be drawn at 5-minute intervals. This allows for a more accurate setup. The sundials are designed for a latitude of 45 but the dial plate can be adjusted over the latitude range of 25 to 45 by raising the north or south end. As a result there are many pieces to the sundial but it is not difficult to put together.

Figure1: Horizontal/Analemmatic Sundials Kit

Figure 1: Horizontal/Analemmatic Sundials Kit (ZW2000/CAD)

We have made up two kits so that you can build a combination horizontal/analemmatic sundial for the Northern or Southern Hemisphere. All you need are scissors, cardboard, glue and tape. If you would like to download a PDF file of the "Horizontal/Analemmatic Sundials Kit" just open the door that works for you.

Horizontal Analemmatic Sundial  Kit - Northern Hemisphere Horizontal Analemmatic Sundial  Kit - Southern Hemisphere
Northern Hemisphere Southern Hemisphere

When you have completed the sundial all you have to do is set up and it will tell you solar time. To set up the sundial for your latitude first determine if you must raise the north or south end of the dial plate.  This is easily done by looking at the latitude scales. Place thumb tacks at your latitude on the scales. This will help to keep the dial plate from moving down. The tab at the opposite end of the dial plate will hold it at the top of the box. The dial is self orientating and all you need to do is rotate it until both the horizontal and analemmatic sundials read the same time. If you are comparing the time to a clock remember to adjust the time for the Equation of Time and longitude correction. The "Correct-A-Dial" or "Correct-A-Dial II" will help you here. And if the clocks are set to summer time don't forget about the one hour (or whatever) difference.

When the sundial is correctly set up you can mark the north, south, east and west points using the arrows on the side of the box. You now have the true north-south or local meridian line as well as an east-west line. These can be used to set up all the other paper sundial kits you make as they all indicate solar time.

Here's what the sundial will look like once you have finished making it. This one is located in the Northern Hemisphere and positioned for a latitude of 50.  The pictures are intended to help you see the two parts of the sundial.

Horizontal/Analemmatic Sundials - In Operation

Northern Hemisphere - August 7


Horizontal/Analemmatic Sundials - Outer Box: Direction Markers

Outer Box: Direction Markers

Horizontal/Analemmatic Sundials - Inner Box: Latitude Scales & Dial Plate

Inner Box: Latitude Scales & Dial Plate

Horizontal/Analemmatic Sundials - Completed Model

Horizontal/Analemmatic Sundials - Completed Model


Because this sundial is so useful designs have been developed for a more rugged model. These models use laminated paper and rigid styrofoam board for the construction materials. It is very easy to build. If you would like to download a PDF file of the "Horizontal/Analemmatic Sundials Kit" just open the door that works for you.

Horizontal Analemmatic Sundial  Kit - Northern Hemisphere Horizontal Analemmatic Sundial  Kit - Southern Hemisphere
Northern Hemisphere Southern Hemisphere

The following photographs show the completed styrofoam model. Check the fit of the outer box before gluing the sides together to ensure the inner box is not too loosed or tight.  Small adjustments can be made at this point that will be difficult after all the parts are glued. Note that the gnomon for the analemmatic sundial can be oriented in any direction. Only the vertical edge needs to be positioned on the centre line of the date scale and on the correct date line.

Horizontal/Analemmatic Sundials - Outer Box: Direction Markers

Outer Box: Direction Markers

Horizontal/Analemmatic Sundials - Inner Box: Latitude Scales & Dial Plate

Inner Box: Latitude Scales & Dial Plate

Horizontal/Analemmatic Sundials - Completed Model

Horizontal/Analemmatic Sundials - Completed Model

Happy Dialling!