A Clean Division

I examined a dry round walnut shell sitting upon the cutting board. It rolled two millimeters when I touched the board. Spherical imbalance is inefficient. I placed my paring knife vertically into the natural center fissure between the two shell halves. I held the handle with both paws and pressed straight downward with calibrated weight. A sharp crack sounded. The shell split cleanly into two identical, hollow hemispheres. I turned both flat rim faces downward against the maple wood. Neither side rolls now. The surface is completely steady.