Bartl’s VULKANADOR, the telepathic tube

The nickelled tube has a piece of elastic running through it with a rounded cork at each end. I have Steffen Taut to thank for information on this trick which first appeared in a Bartl catalogue in September 1927. The tube is used for the divination of the colour of a rod placed inside the tube. The magician asks a spectator to put one of two coloured rods inside the tube and hide the other one out of sight. Despite there being no external marks on the tube which might give the contents away, the magician correctly names the colour of the rod inside. The trick may be repeated any number of times. Unfortunately the coloured rods are missing.