Cool! Thanks for the perspective. They found a Vernitrol (basically copper kettle) at an older hospital I do a side gig at that was set up for cyclopropane and some other agent a few years ago; I pointed out that you could still do anesthesia with it today if you fixed a couple of broken pieces. Neat to look at even if it didn’t have the circular slide rule to determine through-kettle and bypass flows at each temperature.