These earliest engines are called hand tubs because they are manually (hand) powered and the water was supplied by bucket brigade dumped into a tub (cistern) where the pump had a permanent intake pipe. An important advancement around 1822 was the invention of an engine which could draft water from a water source doing away with the bucket brigade. Philadelphia fire engine manufacturers Sellers and Pennock model the Hydraulion is said to be the first suction engine produced in 1822.[2] Some models had the hard, suction hose fixed to the intake and curled up over the apparatus known as a squirrel tail engine.