Page:Sewell Dikshit The Indian Calendar (1896) proc.djvu/10

I must also tender my warm thanks for much invaluable help to Mr. H. H. Turner, Savilian Professor of Astronomy at Oxford, to Professor Kielhorn, C.I.E., of Gottingen, and to Professor Jacobi.

The Tables have been tested and re-tested, and we believe that they may be safely relied on for accuracy. No pains have been spared to secure this object.

It was only in September, 1893, that I became acquainted with Mr. R. Sewell, after he had already made much progress in the calculations necessary for the principal articles of Table I. of this work, and had almost finished a large portion of them. The idea then occurred to me that by inserting the ${\displaystyle a}$, ${\displaystyle b}$, ${\displaystyle c}$ figures (cols. 23, 24, and 25 of Table I.) which Mr. Sewell had already worked out for the initial days of the luni-solar years, but had not proposed to print in full, and by adding some of Professor Jacobi's Tables published in the Indian Antiquary, not only could the exact moment of the beginning and end of all lunisolar tithis be calculated, but also the beginning and ending moments of the nakshatra, yoga, and karaṇa for any day of any year; and again, that by giving the exact moment of the Mesha sankranti for each solar year the exact European equivalent for every solar date could also be determined. I therefore proceeded to work out the details for the Mesha saṅkrântis, and then framed rules and examples for the exact calculation of the required dates, for this purpose extending and modifying Professor Jacobi's Tables to suit my methods. Full explanation of the mode of calculation is given in the Text. The general scheme was originally propounded by M. Largeteau, but we have to thank Professor Jacobi for his publications which have formed the foundation on which we have built.

My calculation for the moments of Mesha saṅkrântis, of mean intercalations of months (Mr. Sewell worked out the true intercalations), and of the samvatsaras of the cycle of Jupiter were carried out by simple methods of my own. Mr. Sewell had prepared the rough draft of a treatise giving an account of the Hindu and Muhammadan systems of reckoning, and collecting much of the information now embodied in the Text. But I found it necessary to re-write this, and to add a quantity of new matter.

I am responsible for all information given in this work which is either new to European scholars, or which differs from that generally received by them. All points regarding which any difference of opinion seems possible are printed in footnotes, and not in the Text. They are not, of course, fully discussed as this is not a controversial work.

Every precaution has been taken to avoid error, but all corrections of mistakes which may have crept in, as well as all suggestions for improvement in the future, will be gladly and thankfully received.