Yantra is however not so old as Yagya. It was mostly used after 13th Century when Tantra came in influence by Guru Gorakhnath, Matsyendra Nath etc. Tantra was later devided in Right (Positive) and Left (Negative). Both the ways have Mantra, Tantra and Yantra for fair and unfaire uses. Veda never support Left ways of any kind. Yantra is scientifically a diagram which attracts cosmic and planetary energy and works through magnetic inductions system. For Yantra to really work, one needs to make it Sidha and that costs a lot of work, energy and money,
