Essay on the Architecture of the Hindus c4.54

c4.54

bottom to the top." "Around this a circle is drawn with a cord of twice the height of the gnomon, by fixing one end of it to its base and carrying the other around it. Points are marked in the circumference where the shadow of the gnomon projects, both in the forenoon and afternoon, that is at any given hour after sun-rise, and at the same time before sun-set; and between these points a right line is drawn so as to join them; the point marked by the morning shadow will shew the east, and that marked by the evening shadow the west. Then, from each of these two points, and with a radius equal to the distance between them, describe two more circles cutting each other, and resembling (in their points of intersection) the head and tail of a fish, between which draw a right line, which will point to the south and north. Again, from the southern and northern points, which touch the circumference of the inner circle respectively, and with the same radius, describe two more circles, and the points of intersection on the two other sides will indicate the east and west." The text goes on with repeating a similar process for ascertaining the intermediate points. Some treatises require the first circle to be described around the gnomon, not previous to making the morning and afternoon shadows, but afterwards; and in this case, the shadow being marked in the first instance, the circle is described from the centre of the gnomon, with a radius equal to the length of the shadow, plus half the diameter of the gnomon."