The pharynx acts as a suction pump; its muscular walls draw in food. Sani-Floor consists of a suction pump and automatic waste lifting. This equals the maximal height of a suction pump, which operates by the same principle. The predecessor to the vacuum pump was the suction pump. He also said that a suction pump was used in siphons to discharge Greek fire. The suction pump later appeared in medieval Europe from the 15th century. A suction pump is usually used to extract the sand from the seabed.