Abstract: A method and means for using ground water in an aquifer as a heat source and heat sink are disclosed wherein heat is exchanged between the uniform temperature ground water and heat-exchanging apparatus at the earth's surface through a single well bore. The ground water is exchanged between an upper and lower portion of the aquifer, alternatively depending on the operating mode, in such a manner that a stratified lateral flow of the water after heat exchange is produced following natural convective paths in the top or bottom of the aquifer and resulting in wide laminar dissipation of the altered temperature water while avoiding thermal mixing between that water and the remaining uniform temperature water in the aquifer. This manner of exchange provides a continuous flow of heating or cooling water at or near the ambient aquifer temperature without any depletion of the aquifer.

Abstract: A system for correlating condition-indicative signals fed sequentially from a series of sensors, such as thermocouples installed in ports on the surface of a rotating kiln at various longitudinal and angular coordinates along the total length of the kiln, with the signals printout on a multipoint recorder mounted remotely from the kiln is disclosed wherein two photoelectric devices are disposed at fixed points adjacent the kiln for sensing the passage of a series of sensor-location indicator tabs mounted on and rotating with the kiln.