Abstract: A smoker's pipe has a mouthpiece opening formed at the intersection of the walls of a smoke-receiving housing. The smoke is cooled and humidified by passing it upwardly through a body of water, the smoke being introduced into the water by a bubble forming means. The bubble forming means has a plurality of apertures which break the smoke into a plurality of bubble-forming streams to reduce the size of the bubbles and to increase the interaction between the bubbles and the water. Carryover of water into the mouthpiece is minimized by providing a deentrainment chamber in the flow path between the smoke cooling chamber and the mouthpiece. In the deentrainment chamber, the smoke ascends and the water descends to drain gravitationally through a check valve near the bottom of the deentrainment chamber. A modular system is disclosed wherein units may be added or removed to vary the number of cooling stages in the pipe.