How do Uncle Septimus's grandchildren make
use of his beard?

The beard grew longer and longer. It became so long that it dragged several feet behind Uncle Septimus, but he refused to trim it. Sometimes at family dinners he fell asleep in his favorite chair beneath the pecan tree in the front yard. Then the grandchildren took the beard and used it as a jump rope.

In the Salem Witch Trials, the stakes were far greater than in the McCarthy-era trials, as people could receive the death penalty in the Salem Trials.  Twenty people were executed in these trials, the majority of them by hanging.  These people were predominantly female, and, while there were other events similar to it in other Northeastern towns and in Europe, the Salem Witchcraft Trials happened in Salem.  The McCarthy trials did not actually kill anyone, but ruined the careers of many prominent politicians and entertainers.  The victims were predominantly men, as men made up the majority of America's political leadership of the time. Also, McCarthy focused his attention on Washington D.C., but he claimed that the entire nation was infested with Communism and it was his job to stamp it out.  

The McCarthy Hearings were referred to as "witch-hunts" because of their similarity to the Salem witch trials. They both struck fear in the people due to the "guilty until you confess" attitude which ruled the courts. McCarthy accused people of being communists, whereas Abigail accused people of being witches.