Brahmasphuṭasiddhānta

It is found that [this work] was completed in the year 1817 This likely refers to the Vikram Samvat year or a specific scholarly dating convention for the manuscript's completion/compilation context.. In this Brāhma Sphuṭa Siddhānta, there are 1008 āryā a specific Sanskrit meter verses. The first half includes ten chapters: 1. Mean Motion, 2. True Motion, 3. The Three Problems referring to time, place, and direction, 4. Lunar Eclipse, 5. Solar Eclipse, 6. Rising and Setting, 7. Elevation of the Lunar Horns, 8. Lunar Shadow, 9. Planetary Conjunctions, 10. Conjunctions with Stars. The second half contains fourteen chapters: 1. Examination of the Treatise, 2. Mathematics, 3. Further [aspects of] Mean Motion, 4. Further [aspects of] True Motion, 5. Further [aspects of] the Three Problems, 6. Further [aspects of] Eclipses, 7. Calculations of Graphical Representation, 8. Further [aspects of] Observational Corrections, 9. The Kuṭṭaka algebraic method of pulverizer/indeterminate analysis, 10. Further [aspects of] Metrics/Geometry, 11. Sphere Spherics/Astronomy of the celestial sphere, 12. Instruments, 13. Units of Measure, 14. Definitions. Thus, there are twenty-four chapters in this work by combining the first and second halves. Among these, the "Examination of the Treatise" is worth considering, as the author mentions the names and prides of many teachers. For example:

From Lāṭa, the Sun and Moon, the mean points, the ucca apogee, and the lunar nodes are not [correct].

The śīghra conjunction/velocity correction of Mars, Mercury, Jupiter, Venus, and Saturn from the mean are also [incorrect].

The number of planetary revolutions in a cycle, as given by Vāsiṣṭha, are [merely] the footprints of Nandi.

[The calculations] for the mandocca slow apogee, circumference, and nodes are also [incorrect] according to Āryabhaṭa.

Having adopted these, Śrīṣeṇa created the Romaka [Siddhānta], and the [Vasishtha] book.

Having adopted these same [faulty methods], the Vāsiṣṭha was [also] created by Viṣṇucandra.

Between these two, there is never any agreement between observation and calculation regarding eclipses.

Whatever occurs is merely by chance original: "ghuṇākṣara" - a metaphor of a worm accidentally making a mark resembling a letter; therefore, what is the use of these two [Siddhāntas]?—
In these verses, the commentator Caturvedācārya states that the Romaka Siddhānta created by the teacher Śrīṣeṇa and the Vāsiṣṭha Siddhānta created by Viṣṇucandra are criticized. Because Śrīṣeṇa and Viṣṇucandra are not mentioned in the Pañcasiddhāntikā, Brahmagupta must have composed these astronomical treatises after Varāhamihira. After 427 years of the Saka era, and before 550 of the Saka era, these two—the Romaka Siddhānta and the Vāsiṣṭha Siddhānta—had become grossly inaccurate. By confirming this through his own observations, the teacher (Brahmagupta) boldly says, "Whatever occurs is merely by chance." Although he says that Āryabhaṭa's system is flawed in every respect, the teacher (Brahmagupta) composed the book to refute his arguments in many ways. For instance, he refutes the rotation of the Earth:
->If the Earth moves a degree in a prāṇa a unit of time, 4 seconds, then why would it not travel to the path of the star?

If there is a rotation of the Earth, why do tall objects not fall down?