SUNDIAL SECTIONS:

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History of Sundials

Why the Sun Dial keeps time

Developing and Making Sundials

Sundial Materials

Sundial Hour Lines Lay out

Sundial "Furniture"

Declination Lines of Sundials

Portable Sundials

Interesting Sundials of the World

LAYING OUT THE SUNDIAL HOUR LINES - Page 6

THE SOUTH VERTICAL SUNDIAL: The plane of the south vertical sundial is perpendicular to the plane of the horizon, and faces due south. The construction of the hour lines for a sundial in latitude 35°N is shown in the example.

The STYLE points to the celestial pole. The SUBSTYLE is the 12 o'clock line and lies in the plane of the meridian. The HEIGHT OF THE STYLE is equal to the complement of the latitude, which in this case is 550 (900- 35 ° = 550). Draw the horizontal line FA (This will be the 6 o'clock line). At A draw AC perpendicular to FA (This will be the 12 o'clock line). Draw AD so that the angle CAD is equal to the height of the style, or 55 0. From B, on AC, draw BE perpendicular to AD. Make BC equal to BE; then make AF equal to AC. Draw the line FC. Through B draw a line parallel to FA, cutting FC at L. Through L draw the line LK parallel to AC. With radius BC and centers at C and F, describe the arcs TV and PQ. Divide these arcs into equal parts of 15° each. Draw lines from F and C through the points thus found, until they cut the lines LK and LB, respectively.