The Science of the Shulba: A Study in Early Hindu Geometry c6.27

c6.27

In Sanskrit, the words *sulba* and *rajju* have the identical significance, which is ordinarily "a rope," "a cord." The word *sulba* or *sulva* is derived from the root *sulb* or *sulv* meaning "to measure" and hence its etymological significance is "measuring" or "act of measurement." From that it came to denote "a thing measured" and consequently "a line (or surface)" as well as "an instrument of measurement" or "the unit of measure." Thus the terms *sulba* or *rajju* have four meanings: (1) mensuration—the act and process of measuring; (2) line (or surface)—the result obtained by measuring; (3) a measure—the instrument of measuring; and (4) geometry—the art of measuring. In the ancient literature of the Hindus we indeed find mention of three kinds of measure—linear, superficial as well as voluminal—having the same epithet *rajju*. In the *Śulbas* the measuring tape is called *rajju*. And we further find there the use of the word in the sense of "a line" also. For instance, we have the term *akṣṇayā-rajju* = "diagonal line." Kātyāyana observes:¹ "(The terms) *karaṇī* ('producer'), *tat-karaṇī*² ('that-producer'), *tiryaṅmānī* ('transverse measurer'), *pārśvamānī* ('side measurer'), and *akṣṇayā* ('diagonal') *rajjus* are ('lines')."