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LAYING OUT THE SUNDIAL HOUR LINES - Page 19

The complement of the latitude of the place is equal to the NEW LATITUDE, wherein the sundial becomes a south vertical declining sundial; and the complement of the reclination is equal to the declination of the south vertical sundial in the new latitude. Note: An east recliner will have a west declination, in the new latitude, and vice versa. Having found the new latitude and the declination of the sundial in that latitude, proceed to lay out the hour lines for a south vertical declining sundial according to the construction described on page 112). EXAMPLE: Let it be required to construct an east sundial reclining 35 °, in latitude 39'N. From the formula given above, this reclining sundial will be-come a vertical sundial in latitude 51 ° (90' 39'=51'), and decline in that latitude 55 ° west (90' -35' =55') The twelve o'clock line is at the base of the sundial and lies parallel to the plane of the horizon. The center of the sundial, on the east recliner, is at the left; and at the right, on the west recliner. If the hour lines are drawn on transparent paper, the re-verse side will show the hour lines for a west sundial reclining 35° in latitude 39°N. If Plate VIII is turned so that the 12 o'clock line is perpendicular, we have a south vertical sundial declining 55° W in latitude 90; the morning hours then become afternoon hours. Therefore, in each of these sundials: The GNOMON is perpendicular to the face of the sundial. The STYLE points to the celestial pole.

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