Indian Science and Technology in the Eighteenth Century: Some Contemporary European Accounts c9.100

c9.100

58. In tables of the planets, we remarked another equation, (*schigram*) answering to the parallax of the earth’s orbit, or the difference between the heliocentric and the geocentric place of the planet. This parallax, if we conceive a triangle to be formed by lines drawn from the sun to the earth and to the planet, and also from the planet to the earth, is the angle of that triangle, subtended by the line drawn from the sun to the earth. And so, accordingly, it is computed in these tables; for if we resolve such a triangle as is here described, we will find the angle, subtended by the earth's distance from the sun, coincide very nearly with the *schigram*.