One question is: How many fleeting moments of physical consciousness a decapitated person experiences before slipping away into eternity? A friend seemed to think that decapitated people actually do have a quick moment of consciousness after being beheaded -- NO, MY FRIEND HAS NOT BEEN THERE AND DONE THAT, LOL.
A recent news article said that judicial hangings are actually intended to snap the neck and cause immediate paralysis and unconsciousness, and that some hangings do literally decapitate the victims.
This brings to mind a show I saw on History Channel's Wild West Tech. The show was on executions and had a lot on hanging. What you mention was covered, there is apparently a science to where to put the knot and a formula to calculate victim weight to length of rope and number of turns. The desired result is immediate breakage of neck, which to the best of their knowledge causes quick painless death.
However if they get it wrong you get a result like one I just read about in a bio of Teddy Roosevelt. Apparently in the hanging of a murderess, they got it very wrong and she dangled and strangled for about 25 min, crying and sobbing the whole time. Don't recall if that was a PUBLIC hanging or not.
Public hangings were common till turn of the century depending on locale, and people turned out for them like they were parties, complete with picnic lunches.
I could really see Edward Collins dragging kid Carl and kid Quentin to one of those, to teach the scamps what happened to kids who, in the parlance of the time, were "born to be hung."