One of the simplest devices that have both vertical and horizontal motion is a slide or chute. It may be straight or spiral and is static in nature. Gravity is utilized in order to move materials down and if desired to change the position of the load horizontally. Chutes are common in railways and air line terminal for handling packages and baggage's chutes are also used in department stress particularly in spiral form to ship stock from reserves on the upper floors to the lower selling floors. Where the sliding down process tends to be slow the vibrating chutes are used where the materials are moved downwards through vibrations.