Matsyapurana 124.55

124.55

rohiṇyārdrā mṛgaśiro nāgavīthir iti smṛtā
puṣyāśleṣā punarvasvor vīthī cairāvatī smṛtā //

The sun appears high (on the horizon) when He reaches the centre of Puṣkaradvîpa. He travels over the 1/30th of the world in one muhûrta (a period of 48 minutes). That is to say, the speed of the sun in one muhûrta (48 minutes) is 31,50,000 yôjanas (1/30 of 9,45,00,000). Thus gradually He marches to the south. In His southward course (Dakṣiṇâyana), He travels in the space between Mânasôttara and Meru thrice as much as in the centre of Puṣkara. Now hear of his southward course. He covers the whole circumference of the earth, 9,45,00,000 yôjanas, in course of a day and night. After finishing his southward course when he comes at the equator (Viṣava rekhâ), he travels over (lights up) the north of the Kṣîrasâgara, as well as the Viṣuvamaṇḍala, whose extent all of you now hear. It is 3,21,00,000 yôjanas. In the month of Srâvaṇa the sun in his northern course travels over Puṣkaradvîpa, which is beyond the Gômedadvîpa. The extent of the northern, southern and the middle of this journey should be noted as below. Jaradgava is in the middle, Airâvata in the north and Vaiśvânara in the south. Nâgavîthî is the Uttarâvîthî (_i.e._, northern course begins with Nagavîthî?). Ajavîthî is the Dakṣiṇâvîthî, with Ajavîthî begins the southward course? The asterisms P. Asâḍha and U. Asâḍha, as well as the Mulâ, Asvinî, Bharaṇi, and Krittikâ form the Nâgavîthî. Rohiṇî, Ârdrâ and Mrigaśira are also Nâgavîthî (or Gajavîthî).

And when the sun passes on to the asterisms Puṣya, Aśleṣâ and Punarvasu, then He is said to be on the Airâvatîvîthî. These three Vithîs comprise the Uttaramârga (northern course). When the sun is in Pûrva and Uttaraphâlguṇa and Maghâ, the Vîthî is called Ârṣabhî. Purvâ and Uttarâprôṣṭhapada and Revati are the Govîthî; while Sravaṇa, Dhaniṣṭhâ and Vâruṇî are the Jaradgavavîthî. These three Vithîs form the middle course of the sun. Hastâ, Svâtî and Chitrâ are the Ajavîthî; Jyeṣṭhâ, Viśâkhâ and Maitra are the Mrigavîthî; Mûla, Pûrva and Uttara Âṣâḍha are the Vaiśvânaravîthî. These three Vithîs form the southern route of the sun; now the (chordal) distance between the extreme points of these (Vîthis), each should be noted.—40-60.