MANUALLY OPERATED MECHANICAL INSTRUMENT UTILIZING A MEASURING SCALE WITH VARIABLE LENGTH GRADUATIONS AND A NUMBER OF MATHEMATICALLY RELATED SCALES WITH FIXED GRADUATIONS AND A COMMON CURSOR, USED IN PERFORMING COMPUTATIONS DIRECTLY ON GRAPHS, CURVES AND RECORDINGS, ALSO USED IN READING, PLOTTING, AND INTERPRETING GRAPHICAL WORK-NAMELY, OSCILLOGRAMS AND TELEMETERING DATA; AND IN DIRECT MULTIPLICATION AND DIVISION OF GRAPHICAL FUNCTIONS, AND IN THE READING THEREOF