Page:English translation of the Surya Siddhanta and the Siddhanta Siromani by Sastri, 1861.djvu/37

 (said) east and west points, and it will be the north and south line or the Meridian Line.

. And thus, draw a line through the formed between the north and south points of the Meridian Line; this line will be the east and west line.

In the same manner, determine the intermediate directions through the formed between the points of the determined directions (east, south &c.).

. (In order to find of a given shadow of the Gnomon at a given time, describe a circle in the plane of the Horizon with a radius whose length is equal to that of the given shadow and at its circumference determine the points of the Horizon, the Meridian and east and west lines as mentioned before:) Then describe a square about the said circle through the lines drawn from the centre (of the circle to the points of the Horizon, in such a manner that the square shall touch the circle at ihe cardinal points) and in this circle (towards the western or eastern part of it according as the given time is before or after noon), draw a line (as a sine,) equal to (of the given shadow and perpendicular to the east and west line towards the north or south according as the  is north or south. To the end of this perpendicular, draw a line from the centre). This (line) will denote the direction of the given shadow (at the given time).

. The line representing the Prime Vertical, the six o'clock line or the equinoctial, passes through the east and west points of the Horizon.