What does the following recipe instruction mean?

Cook over medium heat stirring constantly. Cook until candy turns away from the side of pan. Add nuts and vanilla. Spread in buttered dish.
I am trying to make candy. I've heard of soft ball and hard ball and even own a cany thermometer. I'm a novice cook, but I try.

How long should I cook a 6 lb boneless pork butt?

I bought two pork butts, approximately 3 lbs each and will place them in one cooking dish. Should I cook it for about 4 hours at 350 degrees? I don't have a thermometer.