Had a blast reading it. Hope others enjoy it too.
Thanks for this! Some lovely writing: "cold rush" and "hydrogen--an odorless, colorless gas which tends to turn into a universe if left alone for a prolonged period"... and of course the "high-pitched apology."
Captain Ned wrote:
It's really incredible how much those guys were able to accomplish with the technology they had available.
Well, a certain casual attitude toward lab safety seems to have played a role as well, especially for Dewar.
I'm sure he thought he was being careful according to the standards of the day. This was a time when the London sewers would occasionally explode when a worker with a lamp met a pocket of gas, and people dealing with early industrial machinery were getting maimed and killed on a regular basis.
I'm a bit perplexed by the thermometers they were using, however. How do you calibrate your measurement tools to give you an accurate reading of a range you've never before measured? According to this remarkably-of-its-time science film on Helium II
they're inferring temperature from pressure (around the 13 minute mark), and I guess the Ideal Gas Law can give you that even in this regime, but I'm not sure if that's what Dewar and his contemporaries were using -- and it still leaves open the question of calibration. (That film has all sorts of fun stuff, btw, if you can get past the feeling you're sitting in a 1950s classroom).