Standing before an eternal flame reciting a manthra is one way to contemplate the nature of God's creation and how to work in concert with HIS creation - an act of piety and worship.
Fire represents eternal energy of the Universe and worshipping the fire is one way of acknowledging the universal law that everythign is a form of that energy and it pervades the material and living creation though the various forms of energy. It is considered a transition between spiritual and material creations.
Probably this is the reason why many Mahatmas had a fire in their presence and worshipped it. At Sivapuri, Nagole, to understand this concept and to enable everyone to feel the presence of Mahatmas, dhuni pooja is continuing everyday.
The pooja, which started on November 30th by Sri Ekkirala Dwarakanath Jnaneswar, continued on day 2 by Mr Upendra, day 3 by Mr Sai and day 4 by Mr Srinivas.
Jai Sai Master !