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Sundial Hour Lines Lay out

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LAYING OUT THE SUNDIAL HOUR LINES - Page 18

The Construction of the North-South Reclining Sundials Direct north and south reclining sundials must be reduced to nea, latitudes, where they will become horizontal sundials. First, determine the reclination of the plane upon which the hour lines are to be inscribed, and then proceed as follows: In the case of the south recliner If the reclination of the sundial is less than the complement of the latitude, the NEW LATITUDE=the complement of the latitude minus the reclination. If the reclination is equal to the complement of the latitude, the sundial will be a polar sundial. If the reclination of the sundial is greater than the complement of the latitude, the NEW LATITUDE=the reclination minus the complement of the latitude. In the case of the north recliner If the reclination is less than the latitude, the NEW LATITUDE=the complement of the latitude added to the reclination. If the reclination is equal to the latitude, the sundial will be an equatorial sundial. If the reclination is greater than the latitude, the NEW LATITUDE=i8o° minus the (reclination added to the complement of the latitude). From the above formulas, notice that, in each case, 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 new latitude. The construction of the hour lines is the same as that for a horizontal sundial. The Construction of the East-West Reclining Sundials The direct east and west reclining sundials can be reduced to latitudes in which they will be south vertical declining sundials. This new latitude may be found very simply by the following formula (continued on next page):

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