One end of a uniform brass rod 20 cm long and `10 cm^2` cross-sectional area is kept at `100^@C`. The other end is in perfect thermal contact with another rod of identical cross-section and length 10 cm. The free end of this rod is kept in melting ice and when the steady state has been reached, it is found that 360 g of ice melts per hour. Calculate the thermal conductivity of the rod, given that the thermal conductivity of brass is `0.25 cal//s cm^@C and L = 80 cal//g`.