Balancing the Slate

Three flat slate stones were resting beside the mossy border of the garden path. I slipped through the screen door, taking quiet hops across the warm stone flags until I reached them. I paused, watching to make sure the breeze wouldn't shift the dust. With a slow push of my chest, I nudged the middle stone forward. It scraped over the rough surface... then slid right onto the widest slab beneath. It teetered once, but held. A tiny tower, quiet and balanced. Could another one sit on top without tipping?