And what we get is an exponential curve. Now, the y axis is pressure, the X axis is temperature. What this curve tells us is that identical changes on the X axis produces different changes on the y axis. So, for example, if we take an identical change at higher pressures, we see that that produces a greater pressure difference than at lower temperatures. And that is clearly seen because this guy is much bigger than this guy. Now, what this relation doesn't tell us is the slope of the line.