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How to Make a Capuchin Sundial

Before the age of mechanical timekeepers, sundials were the most accurate way to keep track of time. In the 16th century, Roman Catholic monks of the Capuchin Order of Franciscans developed a sundial whose face presumably resembles the shape of the monk's hood. A Capuchin Sundial can be built using simple materials. The Capuchin Sundial is an altitude dial that tells time by the altitude of the sun above the horizon. It is useful only for the altitude for which it is created.

Things You'll Need

Piece of cardboard or card-stock paper
Pencil
Ruler
Protractor
Thread
Small bead
Scissors or other tool for cutting
Medium-sized button

Instructions

- 1
  Cut out a piece of cardboard or card-stock paper, approximately one-foot square. Draw a horizontal line (AB) as long as the width you wish to make the sundial. Draw a perpendicular line (CD) that crosses the middle of the horizontal line (AB), creating a large cross. Where the lines cross (M), place the center of the flat edge of the protractor and draw a semicircle pointed downward.
- 2
  Create 12 divisions of equal width from point M that are pointed downward within the semicircle. Each division should be 15 degrees. For 12 divisions you will draw a total of 10 lines. Between the semicircle and the diameter draw eight vertical lines parallel to the vertical diameter line (CD). These lines will mark the hours on the sundial. The line farthest on the left should start where the left edge of the semicircle crosses AB. The line farthest on the right should similarly start where the right point of the semicircle crosses AB. There will be four vertical lines on each side of CD that are parallel to this line.
- 3
  Draw a line (AE) upward and right, with an angle that is equal to the latitude of your location, or of the general location where you will use the sundial. Point A is the beginning point of your original horizontal line where the semi-circle begins at the left extremity of the sundial. Point E crosses CD on the top half of the line.
- 4
  Draw a line (FG) at point F and perpendicular to AE, which was the line based on the angle of latitude in your location. This will become the date line for the season equinoxes of spring and autumn.
- 5
  Draw a line (AF) from point A at an angle of 23.5 degrees upward from line AE, and a line (AG) from point A, 23.5 degrees downward from AE. F represents the point of the summer solstice and G represents the winter's solstice. From point A, draw 12 lines to line FG. These lines will create delineations for each month (the exact angles vary for each month). Erase any construction lines and write the names of the months in the appropriate locations.
- 6
  Place the left point of the protractor at A and the right point on G. Draw a downward arc (AH). This is the timeline for the summer solstice. It should cross line CD on its bottom half and should cross the hour line second from the right of line CD at the point of the twentieth hour. Repeat this step for the winter solstice with the protractor on A and F, creating an arc, AK. You can write the hours on the scale.
- 7
  Cut out the circle of the sundial and cut a slot for the sun to shine through in one of the corners. From the slot, draw a straight line, which will be parallel to the first line you drew (AB) to the other side of the sundial. Below the slot, make a cut that you can fold up.
- 8
  Insert a piece of cotton thread in the slot with a small weight on one end of the thread, and a small round bead that can slide up and down the thread. Attach a small bottom to the back side of the sundial so that you can slide the thread up and down in the slot. By moving the thread to the current date and aligning the bead, you can calibrate the sundial according to the date.
- 9
  Hold the sundial vertically to allow the sun to shine through. The sunbeam should be parallel to the line on the upper part of the sundial. The thread will provide a plumb line, and the bead will indicate the time of the day.

Astronomy