After Angier finally admits to Telsa what he wants to use the machine for, what does Tesla succeed in making the machine do?

After Tesla is aware that Angier wants to use the machine to transport a man, he gets back to work. The machine is tested on a metal rod and appears to have just made the rod cold. However, Angier later finds another, identical rod, and the two men put it together that the machine has created a duplicate. They test it out with a cat, and there is a hitch, but they do not know what the hitch is.