First, here is a you tube link to see them being made:
http://www.youtube.com/watch?v=EomX7t7to_o
Using one jelly roll you randomly sew all the strips together. They are attached end to end with a diagonal seam. This results in a strip about 1600 inches (!) long. You cut off 18 inches from one end. Take the two ends, rights sides together, and make one seam down one side of what now is 800 inches, cutting the bottom. Then you brings ends together again, right sides together and sew one side, cutting the bottom. You do this until you go from a 1600 inch strip to a 48X64 top. The pattern is really neat, and the you tube link shows several completed tops. It is taking me about an hour to sew the initial strips end to end then about another hour to sew all the seams.