A brass boiler has a base area of `0.15m^2` and thickness 1.0cm. It boils water at the rate of 6kg| min when placed on a gas stove, Estimate the temperature of the part of flame in contact with the boiler. Thermal conductivity of brass `= 10^9J|s|m|'^oC`, heat of vaporization of water `= 2256J|g`?