Droplet Relay

Rain pattered steadily against the glass. I climbed up to the broad wooden sill to get a closer view. Streaks of water raced downward, completely out of rhythm! That wouldn't do. I picked up a smooth plastic ruler resting nearby and propped it diagonally against the bottom frame, creating a clear guiding track. Every time a fat droplet rolled down, it clicked right onto my slope, gliding smoothly toward the corner. One, two, tap! A perfect, steady course.