Bharatiya Jyotihshastra (History of Indian Astronomy), translated by R. V. Vaidya v2.c12.s2.t71.4

v2.c12.s2.t71.4

He has described in detail, the method of taking observations by the quadrant “instrument” and has discussed different new subjects in the chapter on “three problems” and “eclipses”. He has also mentioned that at the time of the solar eclipse, an observer on the moon’s disc will be able to see the earth engulfed in the shadow. He remarks that the Greeks had observed the transit of Venus across the Sun’s disc. The causes of the clouds, hailstorm, earthquake, and the falling of meteors, have been explained by him. They are not wholly true, they are at least not based on superstition and in the truth. His works show some new methods related to the study on arithmetic, geometry, mensuration and trigonometry. Other siddhāntas, assume 3438 units as the radius of the earth, and give values of the sines of angles at intervalsof 3¾°. He has assumed 60 units as the value for the radius of the earth and given values for the sines of each degree, which are very convenient. A table has been given for finding the right ascension of a planet from its longitude. Other Siddhāntas give neither this table nor the method; these are given only in Keropant’s work. In short, his work has many features. It is, however, very difficult to find out how many of them he can claim as his own. It is a matter of regret that original ideas appearing in his work were not further developed.