For those of a certain age, the link below will be enjoyable. It's a preview of the Sunday night CBS lineup for 1961. A brief bit with Jack appears at the 2:45 mark, but I encourage you to view the entire clip. It's astounding to compare TV then and now. The 1961 lineup featured an amazing ten shows! The Jack clip is a classic example of the famous Benny timing.
http://www.youtube.com/watch?v=1b9dN93InR8
Incidentally, Jack's show had been rated 10th in the Nielsen ratings the previous year, but dropped out of the top 20 after that.