@dmuthuk Thirubhai ji recruited one marketing team to take survey before start refinery. They took six months and rejected his idea. It's because lube oil margin is critical factor to run refinery business. They can't beat Castrol , monopoly for decades....but thirubhai ji started it
@HowThingsWork_ Chola dynasty built elephant ramp to construct temple in southern India..it's 11th century..This ramp started few kilometres away to reach top of the temple..They fixed 80 tons of single stone in the top...it's engineering marvellous