# How To Make a Sundial

Sundials go way back in history and reflect man's first attempt to tell the time. As a time teller, a sundial is not in much use today, but it can be a very attractive central piece in your garden. In addition, if you are interested in astronomy and geography, then you could find making your own sundial an interesting activity. You can follow the instructions below to make your own paper sundial; in the process, you will also learn some new terms and some scientific calculation methods too.

Get the following items ready

- Thick Paper of size 30 cm * 15 cm
- Thick paper of size
- Pencil
- Eraser
- Protractor to draw angles
- Scientific Calculator to calculate trigonometric functions
- A pair of scissors
- Transparent tape
- A stiff hardboard

Get to know the latitude of your place (degrees above or below the equator). You can get this information from the internet by looking for this information on a search engine of your choice. Take the paper (30cmX15cm) and place it on your desk with the longer side as the base. Draw the base line of length about 24 cm. Draw a perpendicular line (angle = 90 degrees) going upwards from the center of the base line and of length 12 cm.

Mark the end of this perpendicular line as 12 noon and the left end of the base line as 6 am and right end of the base line as 6pm if you are at a latitude north of equator. (Reverse the marks of the base line if you are at latitude south of the equator).

To mark the time at every one hour interval you need to calculate the angle for each hour to draw the lines accordingly from the base of the 12 noon line upwards. Make a table as shown below to indicate the angle for each hour and use the calculator for the formula: **tan D = (tan t)(sin Ø)**, where ‘t' is the time measured in degrees and arc , ‘Ø' is the latitude of the place and ‘D' is the angle being calculated.

Time Calculation for Line to be drawn at angle

7am

8 am

9 am

10 am

11 am

1pm

2pm

3pm

4pm

5pm

Draw the lines as per angles calculated and mark the time for each line. To make the vertical pointer called gnomon take the 2^{nd} sheet of paper and cut it into a square size of 12cm X 12 cm. Fold the square sheet to make a triangle. Use scissors to cut along the hypotenuse of the triangle at an angle equal to the latitude of your place.

Stick the gnomon with the hypotenuse side facing you and the base along the 12 noon line to using tape to make it stand vertically along the 12 noon perpendicular line.

Your sundial is ready for use by keeping the gnomon in the north direction. Use a magnetic compass to set the direction. Sundials are handsome and an enduring testimony to man's relationship with nature.... One in your garden will make you appreciate this aspect every time you see it!