The poetical and scientific natures rarely coexist; Haller and Goethe are examples which show that such a union may occur, but as a rule the poet is contented with the colors of the rainbow and leaves the study of Fraunhofer's lines to the man of science. Though far from being a man of science, Emerson was a realist in the best sense of that word.
It accordingly forms part of the large sum of Fraunhofer's merits to have secured this inestimable advantage to observers. Sir John Herschel considered that Lassell's application of equatoreal mounting to a nine-inch Newtonian in 1840 made an epoch in the history of "that eminently British instrument, the reflecting telescope."
He pointed out to me that there were certain black lines which formed crossbars upon the series of brilliant colours extending from the red at one end through gradations of orange, yellow, green, blue, and indigo to the violet at the other. "Those dark bands are Fraunhofer's lines," said he. "The colours are just light itself.
Yet at that time the fifteen-inch achromatic of Pulkowa had already left the workshop of Fraunhofer's successors at Munich. It was not indeed until 1845, when the impost which had so long hampered their efforts was removed, that the optical artists of these islands were able to compete on equal terms with their rivals on the Continent.
On the occasion here referred to Kirchhoff also succeeded in reversing a bright band of lithium. The long-standing difficulty of Fraunhofer's lines fell to pieces in the presence of facts and reflections like these, which also carried with them an immeasurable extension of the chemist's power.
"The general blurring and shifting of Fraunhofer's lines of the spectrum point, in my opinion, to a widespread cosmic change of a subtle and singular character. Light from a planet is the reflected light of the sun. Light from a star is a self-produced light. But the spectra both from planets and stars have, in this instance, all undergone the same change.
"What's your opeenion of it, Mr. Malone?" I had to confess my total and humiliating ignorance of the subject at issue. What, for example, were Fraunhofer's lines?
Huggins in connexion with the fixed stars, nebulae, and comets. They, more than any others, illustrate the literal truth of the statement, that the establishment of spectrum analysis, and the explanation of Fraunhofer's lines, carried with them an immeasurable extension of the chemist's range.
When the white light from the electric lamp is sent through that flame, you will have ocular proof that the yellow flame intercepts the yellow of the spectrum; in other words, that it absorbs waves of the same period as its own, thus producing, to all intents and purposes, a dark Fraunhofer's band in the place of the yellow.
At Potsdam, the bright yellow line was perceived with astonishment by Vogel on May 31, and was next evening identified with Fraunhofer's "D." Its character led him to infer a very considerable density in the glowing vapour emitting it. Hasselberg founded an additional argument in favour of the electrical origin of cometary light on the changes in the spectrum of comet Wells.