Yantras or Mechanical Contrivances in Ancient India c2.212

c2.212

The most curious of the yantras described by Bhoja in this chapter is, of course, the one that rises and travels in the air. From the previous notices of this aerial machine only the barest details of its make-up could be gleaned. The only text that gives us some knowledge of its actual construction is this work of Bhoja. Firstly Bhoja mentions the main material of its body as light wood, *laghu-dāru*; its shape is that of a huge bird, *mahāvihanga*, with a wing on each side. The motive force is then explained: In the bowels of the structure, below, is to be a fire-chamber with mercury placed over a flame. The power generated by the heated mercury, helped by the concurrent action of the wings which are flapped by a rider inside, makes the yantra go up and travel far (*dūra*) (95-96).