Presentation on theme: "Design an Analemmatic Sundial For Your Latitude North American Sundial Society Created by: R.L. Kellogg Sept"— Presentation transcript:
Design an Analemmatic Sundial For Your Latitude North American Sundial Society Created by: R.L. Kellogg Sept This is an unusual power point presentation. By enabling the Visual Basic macros, you can create your own Analemmatic Sundial. First, check your power point security setting: Click on Tools, Macro, Security…. Set the security level to medium. To be sure the macros are safe, choose the Alt + F11 keys to review the Visual Basic code (Modules, Module1). Exit the Visual Basic code and Power Point program. Restart power point and respond to the dialog box enable macros. This will be the normal startup to activate the program features. There is no need to view the Visual Basic code when the power point program is used for sundial construction. 1. Start power point (in medium security mode) and enable macros 2. On the next viewgraph, the sundial construction slide, enter your school name in the text box. Do not delete this box nor move it in front or in back of any other object. If you do not care for a name on your sundial, move the text box to the bottom of the slide. 3. At the top of power point, select slide show and view show. 4. Go to the next slide for dial construction. Click the up and down arrows to select your latitude (+ for north, - for south). 5. Click the Draw Dial button. Power Point will draw your Sundial. 6. You may select other latitudes and Draw Dial again and again. It clears the display before drawing. 7. You may clear the dial and gnomon by selecting Clear 8. End the slide show and print out the Analemmatic Sundial slide. 9. No need to cut out the dial. All you need is a vertical gnomon to cast the shadow. A soda straw or pencil and a bit of clay to hold it work well. Be inventive to find your own gnomon. Its height does not matter. 10. Place the Sundial in a sunny spot with the 12 oclock hour of the dial pointed North (South for Southern Hemisphere). Place the gnomon on the center line for todays date. Read the time. This is local solar time and may differ from your clock standard time. You can use the Equation of Time graph to correct the sundial to standard time. Variability in the earths orbit around the sun, the earths axis tilt, and the sundial location away from the longitude of the time zone may cause the Sundial to be up to 45 minutes off.