Abstract: A matric potential sensor comprises(a) a housing including a porous wall adapted to be located underground,(b) spaced metal plates carried in the housing to be coupled to a source of electrical current, and(c) granular material located to pass electrical current within the housing and between the plates so that the current flow will vary as a function of the moisture content of the granular material, said content adapted to vary as a function of the matric potential of the soil surrounding the housing in response to moisture transmission through the porous housing into the surrounding soil.Special circuitry adapts the sensor for use with a solenoid type irrigation valve controller.

Abstract: A surface controlled, sub-surface well valve includes a main valve, a main valve actuator, and a control pressure responsive pilot valve to control application of control pressure to the actuator. The construction is such that the effects of excessive control pressure due to well depth are obviated.

Abstract: A multiple fuel burner assembly, especially suited for use in kilns, includes:A. a forwardly elongated inner duct to deliver pulverized solid fuel to a burning zone beyond the end of the duct,B. multiple pipes spaced about the inner duct and opening generally forwardly to deliver fluid fuel to said zone beyond the ends of said pipes, andC. air delivery structure located outwardly of said inner duct and oriented to deliver air to the fuel delivered from said pipes and inner duct to said zone for combusting said fuel.