Two men are plowing a very large field. Starting at opposite ends they gradually approach each other, but leave unplowed a strip through the center (about 10 to 12 feet wide) of the field. On this unplowed strip a tractor is to drag a large log across the field. It was first planned to fasten the drag chain to middle of log, but this seemed likely to cause the log to become snagged on the large clods of the plowed ground, and so the chain was attached to one end of the log.