When you think about some of the great feats of modern engineering, it is unlikely that the image that springs to mind contains marbles. Surprisingly however, the marbles that have absorbed countless childhood hours have gone on to inspire engineers to create some of the most intricate contraptions to have graced the real world. The concept of marble machines has been around for decades, and the marble run, or rolling ball sculpture, has grown into an art form, with the kinetic sculptures featuring multiple overlaid tracks, switches and even musical instruments triggered by a trail of moving marbles. The machines themselves are complex, providing a hypnotizing cycle of marbles around a track. The process becomes even more engaging when an electrical motor is added, making the reloading process fully automatic.