The restless mix of ambition and curiosity that had spurred William Huggins down so many unexplored paths in the past would not let him sit quietly upon the laurels he had earned. The discovery of terrestrial helium and the puzzle of radium's spontaneous glow brought him new brinks to teeter on, fresh risks to calculate, and undreamt-of wonders to reveal. Because the published record of his research in these areas is scant and unrelated to his more familiar astronomical investigations, Huggins's creative work, particularly on the question of the nature of radium glow, has been ignored by historians of science. In this chapter, that oversight will be rectified. The public record augmented by his unpublished correspondence with fellow investigators bring to light how eagerly and ardently he and his wife, Margaret, applied their spectroscopic and photographic expertise to these new and tantalising problems.

The previous chapter introduced the young American astronomer George Ellery Hale, and discussed the foundation of Huggins's alliance with him. In this chapter, we will follow the growth and development of their close relationship as Hale launched his career in astrophysics and pursued his ambitious plan to erect and direct the world's largest refracting telescope. Huggins nurtured his friendship with Hale, and developed a similar association with Irish mathematician and physicist Joseph Larmor.