Five different, equally sized, metal rods-aluminium,brass,copper,zinc, iron- are radially spread out from each side of a hexagonal, metal hub. Other ends of rods have small recesses to hold paraffin wax. When hub is heated over flame, wax contained in different rods melts at different times, showing differences in thermal conductivities of the rods. With instructions.
No-5309/27, Punjabi Mohalla, Ambala Cantt, Haryana, 133001, India