Cool - the fact about cell phones is astonishing. I always cringe at the false boiling frog metaphor, though. (http://en.wikipedia.org/wiki/Boiling_frog)
The ages of the experiments are irrelevant here because 1) 19th century Germans had thermometers and heaters that were more than adequate for this task. We have no technological advantage over them in this regard
2) The modern experiments weren't building on or refining the old ones because the experimenters weren't aware of them. We only see farther than those who came before because we're standing on their shoulders. If we can't find their shoulders, we don't have that advantage.
There's more about this in the discussion page between two wikipedia edit warriors, on of whom, coincidentally, has the same username that I am using on this site right now.