As focused as the Hugginses were during the 1880s and 1890s on demonstrating the feasibility of their method of photographing the solar corona without an eclipse, they also remained alert to and actively involved in other projects. The astrophysics playing field was becoming crowded with new players – some joining in to assist, others to compete. The rules and even the game itself were constantly changing.

William and Margaret found it both exciting and discomfiting to be involved. To participate successfully required no small measure of vigilance and alacrity: vigilance to defend one's claims to priority of discovery and reputation as an observer; alacrity to keep abreast of the latest investigatory opportunities, technical improvements and methodological innovations. William Huggins had always possessed these characteristics, but as both his career and astrophysics matured, he and Margaret had to remain alert and ready to act to preserve his role as patriarch in the field and maintain what both of them believed was William's rightful place in the history of the new science.

Like their corona work, their investigation of the so-called ‘chief nebula line’ was a project in which Margaret was actively involved. It embroiled the Hugginses in controversy over methods, instruments and interpretation of received data. Their findings formed the basis of the first paper on which Margaret Huggins appeared as co-author. This paper, which appeared in 1889, was a benchmark in the Hugginses' collaborative relationship.