Ptolemy's Tetrabiblos · Ptolemy
THE DEGREE ASCENDING
There frequently arises some uncertainty as to the precise time of birth, and some apprehensions lest it should not be accurately noted. In most cases, the actual minute of the hour, at which the birth happens, can only be ascertained by making a scientific observation, at the time, with an horoscopical astrolabe[112]; for all other instruments, employed in ascertaining the hour, are almost fallacious, although used by many persons with much care and attention. The clepsydra,[113] for instance, is subject to error, because the flow of the water will, from various causes, proceed irregularly: and the sundial is often incorrectly placed, and its gnomon often distorted from the true meridian line. To obviate the difficulty arising from the inaccuracy of these instruments, it seems highly necessary to present some method by which the actually ascending degree of the zodiac may be easily ascertained, in a natural and consistent manner. And in order to attain this essential point, it is necessary first to set down the ordinary degree which, by the Doctrine of Ascensions,[114] is found near the ascendant at the presumed hour. After this has been done, the new or full Moon, whichever it may be, that may take place next before the time of parturition, must be observed: and, if a new Moon, it will be necessary to mark exactly the degree of the conjunction of the two luminaries; but, if a full Moon, the degree of luminary only which may be above the earth during the parturition. After this, it must be observed what planets have dominion over the said degree: and their dominion depends always on the five following prerogatives, viz. on triplicity, house, exaltation, terms, and phase or configuration[115]; that is to say, a planet, eligible to dominion, must be connected with the degree in question either by one, or more, or all of these prerogatives.
It must however be observed, that if the actual distance of the degree, in which the ruling planet may be posited, from the ordinary degree ascending, be found to exceed its distance from the ordinary degree of the mid-heaven; the numerical denomination, found in the way above mentioned, is then to be considered as applicable to the actual degree in culmination; and the other angles are to be arranged in conformity therewith.[117] [116] Or, on the ascendant. [117] The precepts delivered in this Chapter have obtained the name of Ptolemy’s Animodar: the term is probably Arabic, if it be not a corruption of the Latin words _animum_, or _animam_, _dare_, “giving animation or life”; yet this meaning seems scarcely close enough.
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