Yantras or Mechanical Contrivances in Ancient India c2.160

c2.160

Chapter 31 of the *Samarāṅgaṇasūtradhāra* is called *Yantravidhāna* and its 224 verses are wholly devoted to a description of various mechanical consructions. Bhoja opens with the definition of yantra, that it is so called because it controls and directs, according to a plan, the motions of things that act each according to its own nature. As we have seen and as Bhoja explains, it is from the principle of control, *yam*, that the name yantra is derived (3, 4).