The Grain Drill.

     This is a Grain Drill. A drill, in this case, is an implement that plants seeds. Not surprisingly, this one plants grain. More specifically, it recently planted spring wheat. This is accomplished by a fairly simple process that has been refined over millennia.

     The large boxy part on the top is just that, a box. Inside is where you put the seeds. Just beneath the box is an unseen mechanism that allows the farmer to set the rate at which seeds will be allowed to fall.

     Above is a view from the front. The seeds fall down to these. Each one is a pair of disks behind a small prong. The disks are angled so that the gap between them is narrow in the front  and wide at the back. When you pull forward the prong will gouge out a small groove in the soil and the rotating disks will lift and separate the sides of the groove.

     This time, the above view is from the rear. While the disks have the side of the groove separated the seeds fall in between them. The chains trail behind to knock the sides of the groove in, burying the seeds.
     As you can probably figure, you can plant a lot of seeds in a very short amount of time with a drill. The major innovation of the drill, though, is that the seeds are planted in a uniform and organized fashion. This allows for optimal growth in the planted crop and that they will also grow at the same rate. Uniform crops with optimum growth makes for an easier, more fruitful harvest. Which ultimately results in more food!