Abstract: An absolute gravity inline measuring apparatus includes an interferometer arrangement, a test mass tracking system, and a superspring mechanism. The interferometer arrangement includes first and second beam splitters for respective splitting and recombining a laser light beam and upper and lower cornercube retroreflectors facing toward one another and spaced above and below the first beam splitter so as to reflect one split portion of the laser beam in vertically-aligned upper gravity measuring and lower motion compensating portions of a variable leg of the interferometer light beam path. The test mass tracking system includes a cart vertically movably in an evacuated elongated housing and releasably supporting a test mass in a drag-free enclosure. The test mass incorporates the upper retroreflector of the variable leg of the interferometer light beam path.

Abstract: Disclosed herein is a fishing reel having as its principal features a manually adjustable, automatic, drag differential which applies greater resistance to rotation of the line spool in the line letting out rotation than in the winding up direction; a closely related manually engageable brake for selective added resistance to spool rotation in the letting out direction; a dynamically balance free-standing spindle and removable line spool combination wherein the two are interlocked for joint rotation, while spools may be easily and rapidly interchanged in a spindle as desired; and the structure in the spool side walls with an arrangement of cutout portions which provide dynamic balance and substantially vibrationless high speed rotation and lightness in weight and ventilation of the spool, without the requirement for addition of counter weights for balancing the spool.