The New Astronomy

Abstract

One of the great dramatic events in the history of astronomy occurred in 1859 (a momentous year that also marked the publication of Charles Darwin’s Origin of Species), when Robert Bunsen and Gustav Kirchhoff in a laboratory in Germany resolved the long-standing mystery of the dark gaps in the spectrum of the Sun. The first to observe such gaps in the Sun’s rainbow colours was the experimental chemist and polymath William Hyde Wollaston, already mentioned as a dear friend of Mary Somerville to whom he demonstrated the phenomenon in his home soon after she arrived in London.

In the course of time many hundreds of gaps or lines were identified in the solar spectrum. Their true cause, however, remained a puzzle: all that could be said was that they were caused by some absorbing material either on the Sun itself or in the Earth’s atmosphere, or both. (The Piazzi Smyths had made observations pertinent to this problem on Teneriffe in 1856 (Chapter 8)).