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chapter:
INTRODUCTION
CHAPTER I: THE ZODIAC AND THE PLANETS
CHAPTER II: THE PHASES OF THE MOON
CHAPTER III: THE COURSE OF THE SUN THROUGH THE TWELVE SIGNS
CHAPTER IV: THE NORTHERN CONSTELLATIONS
CHAPTER V: THE SOUTHERN CONSTELLATIONS
CHAPTER VI: ASTROLOGY AND WEATHER PROGNOSTICS
CHAPTER VII: THE ANALEMMA AND ITS APPLICATIONS
CHAPTER VIII: SUNDIALS AND WATER CLOCKS
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BOOK I
BOOK II
BOOK III
BOOK IV
BOOK V
BOOK VI
BOOK VII
BOOK IX
2. Hence, wherever a sundial is to be constructed, we must take the equinoctial shadow of the place. If it is found to be, as in Rome, equal to eight ninths of the gnomon, let a line be drawn on a plane surface, and in the middle thereof erect a perpendicular, plumb to the line, which perpendicular is called the gnomon. Then,from the line in the plane, let the line of the gnomon be divided off by the compasses into nine parts, and take the point designating the ninth part as a centre, to be marked by the letter A. Then, opening the compasses from that centre to the line in the plane at the point B, describe a circle. This circle is called the meridian.
Vitruvius: The Ten Books on Architecture. Vitruvius. Morris Hicky Morgan. Cambridge: Harvard University Press. London: Humphrey Milford. Oxford University Press. 1914.
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- Lewis & Short, circĭnātĭo
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