Madhyahnakalalagna in Karanapaddhati of Putumana Somayaji

By : Venketeswara Pai R., M. S. Sriram

Page No: 55-74

Abstract
Madhyahnakalalagna is the time interval between the rise of the equinox and the instant when a star with a non zero latitude is on the meridian. Algorithms for finding the Madhyahnakalalagna are given in the text Karaõapaddhati of Putumana Somayaji. These have no equivalents in the other Kerala astronomical works. Only a person with a great deal of insight into the subject of spherical trigonometry could have arrived at these algorithms. In this paper, we present four algorithms to find the Madhyahnakalalagna as described in the text. We also provide the detailed derivation of two of them, adopting the method of Yuktibhasha for such problems, as it is very likely that the author would have followed such a method.