^horray for old (1944) education videos. Went down the rabbit
   trail (or through the looking glass) and ended up here somehow.
   The man's voice is CLASSIC real old school education film - and
   he actually PAUSES long enough for students to take notes, gives
   you a moment to absorb it, before moving on. Graphics remind me
   of Flash videos when they first came out. Great old stuff.

   It would take too long to explain HOW I ended up here - oh,
   fine, I'll say it - i'm longwinded anyway - I live in sw
   florida, know that evaporative coolers don't usually work at all
   here, just learned about the Joule-thomson effect (gas going
   through a nozzle makes things cold - think about the "Canned
   air" dusters you might use to clean your computer keyboard - how
   it freezes - or a propane tank gets ice on it). Got me curious,
   wondering if there was a way an air compressor could easily be
   used to make "cold", but before I figured that out, I saw this.^