The Oscilloscope: a Stabilized Cathode-Ray Oscillograph with Linear Time-Axis

A method is described for using a cathode-ray oscillograph for the simultaneous observation of a number of variable quantities by means of a distributor. A linear time-axis, obtained by means of a gas-discharge lamp connected to a source of direct-current through a resistance or thermionic tube, is stabilized by introducing into this circuit a small e. m. f. derived from the same source that supplies the unknown quantities under observation. By making stabilization definitive rather than casual, distortion is avoided. The unknown quantities are thus shown in a form convenient for observation, appearing as stationary curves plotted with time as abscissa. The curves may be superposed about a common zero line, or displaced with reference to each other with separate zero lines. The name oscilloscope is applied to the apparatus here described, assembled as an instrument.