This is our first time (as an engineer) seeing this type of graph that we can't interpret. This is a rough comparision of thermal conductivity from the Wiki page. http://en.wikipedia.org/wiki/Thermal_conductivity
What we know The more we go in the log x axis, the more conductive the material is. Say, silver vs insulation fiber.
What we don't know What the length of each bar presents (in terms of y axis). Say, why silver bar is 3 times the copper and what does it mean.