A text-book of general astronomy : for colleges and scientific schools (1888)
Young, Charles A. (Charles Augustus), 1834-1908 · Boston ; London : Ginn & Company · leaf 211
FlG. 111.Comparison of the Solar Spectrum with that of Iron. From a Negative by Prof. Trowbridge. fessor Trowbridge at Cambridge. The lower half is the violet por-tion of the spectrum of the sun, and the upper half that of the vaporof iron in an electric arc. The reader can see for himself with…
Astronomy
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