Indian Science and Technology in the Eighteenth Century: Some Contemporary European Accounts c8.18

c8.18

A, *b* are circular walls; *a* is 24 inches thick, and near 16 feet radius; *b* is concentric with *a*, 18 inches thick, and between 12 and 13 feet radius. *C* is a cylinder of stone, its center is the center of the walls. *B* and *C* are of equal height, viz, 4 feet 2 inches; the outward wall is 8 feet and 4 inches. The tops of these walls are horizontal, and are very nicely divided into degrees, and subdivided into arches of 6'. At the cardinal points on the top of the wall *a*; there are two iron pins, from which I conjecture there has been an instrument to fix upon the wall, though I do not know for what purpose or of what kind.