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JUNE, 1888.]
JACOBI'S TABLES FOR HINDU DATES.
145
METHODS AND TABLES FOR VERIFYING HINDU DATES,
TITHIS, ECLIPSES, NAKSHATRAS, ETC. BY HERMANN JACOBI, PH.D.; PROFESSOR OF SANSKRIT IN THE UNIVERSITY OF KIEL. THE Tables which are now placed before the relative distance by twelve degrees of the
publie, are intended for the use of those zodiac. The names of the tithis are the who wish to verify dates of Indian docu- Sansksit ordinals,-prathamd, dvitiya, etc. ments, inscriptions, manuscripts, etc., The first tithi of either paksha is also called chronicled according to the intricate Luni-Solar pratipad or pratipadá; the last tithi of the Calendar of the Hindus. The working of these bright fortnight is also called purnima, as Tables will be found easy, requiring only the it ends with the moment of full-moon; and computation of a few figures; and the operation the last titki of the dark fortnight, amávásyú, to be gone through is almost mechanical, and as it ends with the moment of new-moon. will yield correct results, if the rules, to be The tithis furnish the names of the civil days, explained in the sequel, be strictly adhered to. inasmuch as the civil day (being accounted to Nevertheless, to render more intelligible the begin with true sunrise) is named after the process of calealation, it will be well to place tithi that ends in it. Thus, Mâghê ba di 9 is before the reader the frame and outlines of the the usual abbreviation equivalent to the civil Luni-Solar Calendar.
day in which ended the 9th lithi of the dark
fortnight of the lanar month Magha." PART I.-ON THE LUNI-SOLAR
On Mean and True Lunar Months and Tithis. CALENDAR.
The sun and the moon do not move with an On the Lunar Months, Pakshas, and
even motion ; i.e. they do not always move in Tithis in general.
the same time through the same space of the A lunar month is the time of one lunation. firmament. Yet, for the sake of calculation, It consists of two pakshas, or fortnights,
it has been found convenient by astronomers the bright (sukla, suddha) fortnight, or the to assume that the motion of all the heavenly time of the waxing moon; and the dark bodies is proportional to time. This motion is (krishna, bahula) fortnight, or the time called the mean motion, to distinguish it froma of the waning moon. In the North, the the true motion, dark fortnight precedes the bright fort- The place in which the sun or moon would night; in the South, it follows it. But the be, if they had the mean motion, is called bright fortnight is always the same, both in their mean place. In the same way, mean the South and the North of India. The lunar lunations and mean tithis are spoken of. But, month takes the name of that solar month, in in the Hindu Calendar, only true lunations and whieh occurs the true new-moon forming the true tithis are used ; i.e. true, not as would be commencement of the bright fortnight of the found by actual observation, but as calculated lunar month under consideration. The new- according to the astronomical theory of the moon (the first if there are two) in solar Siddhantas. A. mean lunation, or lunar month, Chaitra, (or Karttika for some eras) forms the is about 29 days, 13 hours; while the true lunar beginning of the luni-solar year. Each paksha month varies in length between 29 daye, 40 is divided into 15 tithis. Atithi is the time minutes, and 30 days, 1 hour, 15 minutes. The required by the combined motions of the sun duration of a mean tithi is about 23 hours, 37 and moon to increase in the bright fortnight)minates; that of a true tithi varies between or to diminish (in the dark fortnight) their about 20 and 26 hours. It is very easy to
Tables 5 to 11 are constructed on the plan of those of according to the elements and theory of the Sarya. Largeteau, first published in the "Connaissance des Siddhanta as will be explained at the end of this paper. temps" for 18-16. By the Tables of Largeteau, the true I have to thank Dr. Peters, Professor of Astronomy in place of the moon in relation to the sun can be found Kiel, now in Königsberg, with whose kind assistance with high degree of accuracy according to the lunar
I have come to a thorough understanding of the conand solar theories of modern astronomy. In order to
struction of Largeteau's Tables. make the Tables of Largeteau serve our purpose, Apart | Compare the scheme, ante, Vol. XVI. p. 143. only of them could be used. The rest had to be altered
