O INTRODUCTION li ,K 6, Yalaya observes : अव्र कालक्रियापादस्य सूर्यदेवेन यज्वना कृतव्याख्यानं समग्रमपि सर्वदा गणितव्यवहाराणां व्याख्याने व्यवहारस्य [उपकारि]त्वात् कालक्रियापादोपदेशभगणावीन् श्लोकॅनिबद्धय स्फुटानयनं श्रीबालादित्यसुतसूर्याचार्यशिष्येण यल्लयाख्येन मया किञ्चिद् [उच्यते] । अादौ गुरुदेवतानमस्कारपूर्वकग्रन्थारम्मः क्रियते नत्वा [शिवं सूर्यगुरु] गणेश वाणीं ग्रहानार्यभटोक्तमार्गात्। श्रीयल्लयाख्यः कुरुते सुवृत्तैर्मध्यग्रहाद्यानयनप्रकारम् ॥ This is followed by the depiction of the planetary parameters, the method of computing the mean planets and allied matters and the demonstration of the computation of mean planets by an example for a date in A.D. 1480. It may be noted that it is in this context that Yallaya mentions the location of his native town of Skandasomesvara. 6. Weights and measures Since a knowledge of the units of measures and weights is essential for mathematical and astronomical computations and since Suryadeva does not supply this need, Yallaya attempts to give the same in detail at the commencement of the Kalakriya-pada. The units depicted by Yallaya relate to length, grain measure, weight, time and numerical notation upto 29 places. This is followed by a statement of the Puranic legend on the promulgation of numerical notation and mathematical operation during a conversation between Lord Siva and Goddess Parvati. 14. ACKNOWLEDGEMENTS The credit for undertaking the present Aryabhatiya Critical Edition Series, of which the present volume forms Part III, goes to the Indian National Science Academy. Prof. F. C. Auluck, VicePresident of the National Commission of History of Sciences in India ་་་་་་་་་ Academy, and Dr. B. V. Subbarayappa, Executive Secretary of cademy evinced keen interest in the progress of the volume at all stages and I am thankful for all the help and advice they have rendered in the preparation of this volume. the I. It was originally intended to include Yallaya's Supplement to present edition of Suryadeva's Commentary, but the idea had to be aband loned on account of the highly corrupt nature of the available manuscript thereof.
