The sure-footedness of mules has enabled trainers to teach them, in several cases, a very effective and showy trick—that of walking over a number of empty bottles placed upright on a floor or platform. This feat is always highly successful wherever performed, and it is really an excellent one. The bottles used are large, stout porter bottles, which will readily sustain a great weight if placed directly on top. To teach the trick the bottles are at first secured in a platform composed of a double thickness of planks, in the upper one of which holes are cut. In these holes the bottles are placed; the bottoms resting on the lower layer of planks, while the upper one holds them securely in place.