I want to know the answer to the following question:
What were gold contacts attached to to increase signal output?
All the background I'm provided with is that "From November 17, 1947 to December 23, 1947, John Bardeen and Walter Brattain at AT&T's Bell Labs in the United States performed experiments and observed that when two gold point contacts were applied to a crystal of germanium, a signal was produced with the output power greater than the input.". Is that enough to answer the question?