Gentle heating at the centre melts wax placed in the hollows at the end of each strip.
strips of copper, brass, steel and aluminium mounted on a wooden ring and meeting in the centre.
Rates of conductivity in the different metals can be compared by the difference in time taken for each cup of wax to melt.

Physics School Lab Equipment Suppliers in India 

Ltekonline are the manufacturers of Conductivity of Metal Apparatus Heat Lab used to demonstrate engineering principles in Engineering Colleges, Engineering Schools and Physics Lab Experiments for Engineering Teaching Lab in Universities