Brihat Samhita of Varahamihira

CH. 2.] BRIHAT SAMHITA.
5

He must know the length, in yojana approximately 5 miles, of the daily motion of each planet in its orbit and of the orbit itself, and generally the length, in yojana, in every case.

He must know the Earth's revolution round the sun and its rotation round its axis; its shape, size, and the like; the latitude of a place and its complement; the nature of the hour circle; the châra dala kala the difference between 6 hours and half a day; the times of the rising of the Zodiacal signs. He must also be able to calculate time from shadow and shadow from time and to convert longitude into right ascension and right ascension into longitude.

He must be able to meet objections and questions in clear and distinct language and must be capable of explaining the science in its purity in just the same way as separating the pure gold from all dross and making it capable of retaining its value when submitted to the touchstone, to the fire, and to the hammer.

How can one, who is incapable of entrapping others with a hard question, or of answering any that is put to himself, or of explaining his views to his students, expect to become an astronomer?

The fool whose exposition is at variance with the text and whose illustration is opposed to such exposition is not unlike one who, addressing Brahma as Parvatti the Goddess, consort of Shiva, begins his praise by recounting the vices of a prostitute.

The predictions of one, who knows astronomy well, who is able to calculate the exact Lagna rising sign with such helps as the shadow, water, and astronomical instruments, and who is well versed in horoscopy, will never fail.