In the beginning, the scientists tried to place two ordinary metal contacts on the surface of the germanium crystal. The problem was to bring these contacts sufficiently close to each other, to obtain the transistor effect. The contacts needed to be within a few hundredths of a millimetre, about the thickness of a paper, and this was very hard to achieve with conventional metal wire contacts. With the use of the two point-contacts created by the slit in the gold foil, the contacts could be placed within a distance of 0.05 mm of each other.