Abstract: A line marker including hollow shell halves assembled about an elevated line and luminous tubes mounted on the shell halves illuminated by the electric field extending about the power line and without electrical connection with the power line itself.

Abstract: A power-line marker comprising a pair of hemispheric shells with open ends facing each other collectively forming essentially a sphere. On the ground, the shells are joined together in a region located on one side only of a line-receiving channel defined between the shells. While in the air, the shells are partially separable from each other, in clam-shell fashion to enable a line to be advanced into the marker ultimately to lodge in the channel. Wire anchoring assemblies protrude from the exterior of the marker used in securing the marker to a line.

Abstract: A method and apparatus for regulating electrolyte solution level in a liquid rheostat. The liquid rheostat is used to control the motor speed of a primary pump which is operable for pumping liquid from a well. The liquid rheostat includes an electrode compartment mounted above an electrolyte solution reservoir and solution from the compartment may drain into the reservoir. A conduit interconnects the reservoir with the compartment and a circulating pump, driven by a variable speed electric motor, is operable for delivering solution from the reservoir to the compartment. A sensor is immersed in the well and develops a signal proportional to the amount of liquid in the well. The signal is received by a motor control which operates to vary the speed of the circulating pump motor, and thus the solution level in the compartment, reflective of liquid level in the well.

Abstract: A liquid rheostat includes a conductive element which surrounds multiple electrodes. The element provides a multiplicity of current paths between the electrodes at a given depth of electrolyte solution thus decreasing current concentration of the electrodes. In order to further decrease current concentration, cylindrical electrodes are used. In a second embodiment, the liquid rheostat and an electrolyte storage container are disposed so as to surround a fluid transport pipe of a pumping system, the fluid being transported in the pipe serving to cool the electrolyte. The rheostat and storage container combined with the pipe provide a compact arrangement for saving space in a pump installation.