Copper, Brass, Aluminium, Steel bars set in holder.
Use with Beaker, do not expose directly to flame.
Effective display of conductivity of different metals.
Instructions:
Fill beaker with hot water *60 deg and over. Dip the exposed end of the apparatus into the water and watch the colour change on each metal. Note: Each 1cm 'blackish' square should become more transparent/brighter depending on the conductivity of the metal.