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tronomer for Scotland on an unsigned post-
card.[18] Its spectrum was observed and pho-
tographed by Huggins and many others. It
was full of bright lines of hydrogen, calcium,
helium, and others not identified. The as-
tounding fact was that lines were shown in
pairs, bright and dark, on a faint continuous
spectrum, indicating apparently that a dark
body approaching us at the rate of 550 miles
620