(I also know what an enema is) Thanks, all, for the fun(ny) brain fart moment I had yesterday. After committing myself to the question of how a rotary mower works, and "enjoying" the "cup of stupid" first thing in the morning, I only THEN remembered that many years ago, I had the same question, and it was answered, and in the intervening years, I forgot. So, I know, AGAIN, how this works. Will I forget ...