Just my idea. I would start with the way grain was harvested years ago. Starting with a hand scythe, gathering the cut grain and stalks. Running the material thru the thresher. Seperating the grain. grain going to the sacks and then the sack sewers sewing them. one word, Combine! Show them the difference between yesterday and today. I think I have a cut-away drawing of the new Deere's and how the salesmen say they work! If I can help more let me know Bob One word