Keywords: SpectroscopyResearch 003.jpg From measurements of these patterns constants were derived that were at present the best criteria for classification of spectral lines The uppermost spectrum shown is of light polarized perpendicularly to the magnetic field; the lowest spectrum is of light polarized parallel to the magnetic field; the center spectrum is of light not under the influence of a magnetic field National Institute of Standards and Technology 8/2/1960 National Institute of Standards and Technology PD-USGov-NIST PD-USGov National Bureau of Standards National Institute of Standards and Technology Spectroscopy |