title: Measurement and removal of ghosts in spectra recorded by modern gratings.
abstract: The Lyman ghosts produced by modern plane gratings ruled under interferometric control are shown to have intensities as high as 1% of the main line. These ghosts may be removed from the spectrum by the use of a relatively large cross dispersion before the spectrograph entrance slit.
authors.forename: J V
authors.initials: JV
authors.lastname: Kline
authors.forename: D W
authors.initials: DW
authors.lastname: Steinhaus