The Rotolactor was invented for one particular kind of huge dairy. But farmers everywhere like to have good machinery to do special jobs.

For hilly country, there’s a plow that has one of its blades higher than the other so it can work on a slope. There are chisel plows that dig up hard soil by clawing at it with strong steel fingers.

One farmer in Texas decided to make his tractor do the plowing all by itself, after he had driven it once around the field to give it a start. He invented a guide

wheel that went ahead of the tractor in the furrow he had made. Now the guide led the tractor around in a spiral that got narrower and narrower until at last it stopped in the center of the plowed field. Another

Texan, with a bigger field and more machines, had a larger idea. He set three tractors loose without drivers, one behind the other. Away they went, round and round. If one traveled too fast and caught up with the one ahead, they stopped. The only work he had to do was go out and start them up again!

There have even been experiments in guiding plows by remote control radio, the way airplanes can be guided. The farmer just sits under a tree and pushes buttons in a control box.