The apparatus is filled with water maintained at boiling point by a low bunsen flame.
The top opening is of 15mm diameter and is fitted with a stopper. .
Infra-red sensors may be used to compare the relative radiant heat output from each of the four faces which are, respectively, blackened, roughened, varnished and polished.
Copper plate box with 100mm sides.

Physics School Lab Equipment Suppliers in India 

Ltekonline are the manufacturers of Leslie Cube Paper Heat Lab used to demonstrate engineering principles in Engineering Colleges, Engineering Schools and Physics Lab Experiments for Engineering Teaching Lab in Universities