Consider the following statements about Sawai Jai Singh's astronomical work : 1. He learnt of the accuracy of European observations, and obtained de La Hire's tables from which he reproduced a refraction table. 2. His astronomers also developed a telescope of their own to observe the lunar phases of Venus. Which of the statements given above is/are correct?
- (a)1 only
- (b)2 only
- (c)Both 1 and 2
- (d)Neither 1 nor 2
Correct — A, 1 only. Statement 1 is exactly what Jai Singh's own work shows. The tables he drew up, the Zij-i Muhammad Shahi, do not rest on his observations alone — they build on existing tables, those of Ulugh Beg and those of the French astronomer Philippe de La Hire, and they adapt de La Hire's figures by correcting for the precession of the equinoxes and for the difference in longitude between Paris and Delhi. A Paris-to-Delhi longitude correction can only mean he had de La Hire's Paris-based tables in front of him, so the transfer of European material, including refraction values, is on the record. Statement 2 fails. The five observatories he built at Delhi, Jaipur, Ujjain, Mathura and Varanasi are equipped from end to end with huge masonry instruments read by gnomon shadow and by naked-eye sighting; no telescope of his astronomers' own making is attested at any of them, and his method stayed a naked-eye method even as he borrowed European numbers.
- (b)2 only — Reverses the truth. The borrowing of de La Hire's tables is documented in Jai Singh's own Zij; an indigenous telescope built by his astronomers is not.
- (c)Both 1 and 2 — Keeps the false second statement. Knowing that European astronomy was more accurate is not the same as building the European instrument; Jai Singh's answer to the accuracy problem was bigger masonry, not optics.
- (d)Neither 1 nor 2 — Throws out the true first statement. Jai Singh's tables openly adapt de La Hire's, right down to a Paris–Delhi longitude adjustment.
Sawai Jai Singh II of Amber and Jaipur (ruled in the early eighteenth century) ran the last great programme of pre-telescopic astronomy in India. He built five stone-and-plaster observatories, had Euclid's Elements, works on trigonometry and Napier's work on logarithms rendered into Sanskrit, invited Jesuit astronomers, and issued a set of tables, the Zij-i Muhammad Shahi, named for the reigning Mughal emperor.
Both statements sound plausible, and the item is decided by knowing which kind of borrowing actually happened. Jai Singh borrowed European data — tables, constants, refraction corrections — and openly so. What he did not borrow was the European instrument. His answer to observational error was to build his sighting instruments enormous, on the reasoning that a bigger arc can be divided more finely, which is why the Samrat Yantra at Jaipur is a masonry gnomon many metres high rather than a lens. That is the historically interesting point the question is aiming at, and the reason statement 2 is the trap. The printed phrase 'the lunar phases of Venus' is the paper's own loose wording for the moon-like phases Venus shows; the slip does not change what is being tested.
- Jai Singh II built five observatories — at Delhi, Jaipur, Ujjain, Mathura and Varanasi.
- His tables, the Zij-i Muhammad Shahi, draw on Ulugh Beg's tables and on Philippe de La Hire's, adjusted for the precession of the equinoxes and for the Paris-to-Delhi difference in longitude.
- He had Euclid's Elements of Geometry, several works on trigonometry and Napier's work on logarithms translated into Sanskrit.
- The instruments at his observatories are large masonry devices read by shadow and naked-eye sighting, not optical instruments.
- The Jaipur observatory is the largest and best preserved of the five and still stands in the centre of the city.
- Assuming that because Jai Singh knew European astronomy was more accurate, he must also have adopted the telescope.
- Treating the size of the Jantar Mantar instruments as decoration rather than as his deliberate answer to observational error.
- Confusing the Delhi Jantar Mantar with the Jaipur one — he built both, and three more.
Asked as a two-statement item that pairs a true fact about borrowed European tables with a false claim about instruments built at home.
Which one of the following statements is NOT correct?
- (a) Ali Mardan Khan introduced the system of revenue farming in Bengal
- (b) Maharaja Ranjit Singh set up modern foundries to manufacture cannons at Lahore
- (c) Sawai Jai Singh of Amber had Euclid's ‘Elements of Geometry’ translated into Sanskrit
- (d) Sultan Tipu of Mysore gave money for the construction of the idol of Goddess Sarda in the Sringeri temple
Answer(a) Ali Mardan Khan introduced the system of revenue farming in Bengal
Same figure and the same theme — how far Jai Singh went in taking up European learning. That UPSC item rests on his having had Euclid rendered into Sanskrit; this one asks how far the borrowing extended into instruments.
CDS_GK_2023_II_Q852023Consider the following statements about science in medieval South India : 1. The Katapayadi system of numerals, which was invented by Vararuchi of Kerala, the author of Chandra Vakyas, was used for calculating the position of Moon on any day of the year. 2. Achyuta Pisharati (1550 – 1621) wrote Uparagakriyakrama, a text on eclipses. 3. Ravi Varma of Mahodayapuram set up an observatory and is also said to have inaugurated the Kollam era. Which of the statements given above is/are correct?
- (a) 1 and 3 only
- (b) 3 only
- (c) 1 and 2 only
- (d) 1, 2 and 3
Answer(d) 1, 2 and 3
Same area — the history of Indian astronomy and the people who built observatories. That 2023 CDS item covers the Kerala astronomers and an early observatory at Mahodayapuram; this one covers the last great pre-telescopic observatory programme, Jai Singh's.
- practice — not a real PYQ
Sawai Jai Singh II built masonry observatories at how many places?
- (a)Three
- (b)Four
- (c)Five
- (d)Six
Answer(c) Five — at Delhi, Jaipur, Ujjain, Mathura and Varanasi.
- practice — not a real PYQ
The set of astronomical tables drawn up under Sawai Jai Singh II is known as
- (a)Zij-i Ilkhani
- (b)Zij-i Muhammad Shahi
- (c)Surya Siddhanta
- (d)Siddhanta Shiromani
Answer(b) Zij-i Muhammad Shahi — named for the reigning Mughal emperor; the Surya Siddhanta and Siddhanta Shiromani are far older Sanskrit works.