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  • Webster's Revised Unabridged Dictionary
    • n Spectroheliograph (Astrophysics) An apparatus for making spectroheliograms, consisting of a spectroscopic camera used in combination with a telescope, and provided with clockwork for moving the sun's image across the slit.
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Century Dictionary and Cyclopedia
    • n spectroheliograph A specialized spectrograph, invented independently by Hale in the United States and by Deslandres in Paris about 1892, for the purpose of photographing the sun by monochromatic light. Its essential feature is a second slit placed immediately in front of the sensitive plate so as to isolate some line of the spectrum, all other light being cut off. The instrument is used in connection with a telescope so pointed as to throw the image of the sun upon the collimator slit. If then this slit is made to traverse the sun's image, and a corresponding motion is accurately communicated to the second slit, the object will be attained. A better plan is to keep the two slits fixed, and to cause the image of the sun to travel across the slit by moving the telescope, while a corresponding motion is automatically communicated to the sensitive plate. This is the arrangement used at the Yerkes Observatory. Deslandres has improved the instrument by placing a second spectroscope ‘tandem’ with respect to the first. The slit which was next the photographic plate becomes the collimator slit of the second spectroscope, while a third slit is placed before the sensitive plate of that spectroscope; this secures a more perfect isolation of the ray which forms the image. The instrument is based upon the fact that the dark lines of the solar spectrum are dark only relatively to the background and are really luminous.
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In literature:

Photographed with the spectroheliograph, using the light emitted by glowing calcium vapor.
"The New Heavens" by George Ellery Hale
Taken with the Spectroheliograph of the Kenwood Observatory, Chicago, by Professor George E.
"A Popular History of Astronomy During the Nineteenth Century" by Agnes M. (Agnes Mary) Clerke
I moved to the lens-box of the spectroheliograph.
"Astounding Stories of Super-Science April 1930" by Various
In the subterranean chamber is the spectroheliograph of exceptional size and power.
"Astronomy" by David Todd

In science:

The launch of the second generation of solar instruments, the NRL spectroheliograph on Skylab and SM M led to lists by Widing et al. (1982) of solar flare lines in the 170345 ˚A range, and by Phillips et al. (1982) of the flare lines in the 5.7 – 19 ˚A range.
Atomic Data for X-ray Astrophysics