Yantras or Mechanical Contrivances in Ancient India c2.213

c2.213

A heavier (*alaghu*) *Dāru-vimāna* is then described (97-98); it contains, not one as in the previous case, but four pitchers of mercury over iron ovens. The boiling mercury ovens produce a terrfic noise which is put to use in battle to scare away elephants; by strengthening the mercury chambers, the roar could be increased so that by it elephants are thrown completely out of control. This specific military use of aircraft against elephants tempts one to suggest that the *Hasti-yantra* advocated by Kauṭilya against elephants was something like the heavier *Dāru-vimāna* described by Bhoja.