They lived on mountains and watched the stars. They hiked through the jungle to observe eclipses. They were the women who helped late nineteenth-century astronomers on their expeditions. Historian Alex Soojung Kim-Pang writes about them in Osiris, raising important questions about how women’s labor has made it possible for men to do scientific research.

Kim-Pang focuses on Elizabeth Campbell, who managed the eclipse-viewing expeditions of the Lick Observatory. She was married to William “Wallace” Campbell, the observatory’s director, and had a central role both in the observatory’s mountainside community of scientists and their families, and in six observatory-sponsored trips to various locations around the globe to view eclipses.

In a time before modern transportation, scientific expeditions “required enormous amounts of supporting labor.” For astronomers intent on seeing an eclipse, the clock was the enemy. If an expedition ran into a hiccup or was mistimed, the scientists risked missing the eclipse. And when it came to coordinating scientific expeditions in far-off lands, Elizabeth Campbell was a formidable organizer. She marshaled massive resources on behalf of the parties she supervised, readying huge numbers of supplies before the expedition, and handling the setup and daily management of camp once the scientists got there.

Kim-Pang describes Elizabeth’s many feats of organization, diplomacy, and sheer will, from organizing scores of scientists and volunteers to getting the locals to help, even when she didn’t speak their languages. Each expedition required huge amounts of organization, planning, and on-the-ground work.

Unlike the male scientists on these trips, who had been socialized to know nothing about domestic life, Elizabeth was prepared to manage every detail of daily life in camp, from toilets to meals, servants to diplomatic visits. She helped manage intricate rehearsals to ensure the actual eclipse went smoothly. And she took pride in her accomplishments. Though her work was largely domestic, Kim-Pang points out, it was also necessary in a time in which scientific equipment was finicky and complex. Elizabeth helped “transfer the observatory into the field,” performing work that was as important as the observations themselves.

Not all eclipse-seekers’ wives were as involved in their husbands’ work. Kim-Pang contrasts Elizabeth with Mabel Loomis Todd, who accompanied her husband David on three eclipse expeditions. But while Elizabeth made the expeditions happen and happily observed the eclipse alongside her spouse, Mabel stayed away from the scientific activity and didn’t even look for the eclipse.

Though she ultimately wrote about the expeditions, Mabel seems to have viewed them more as travel and socialization opportunities than chances to be involved in astronomical fieldwork. But though both women’s experience differed, one thing did not: As women, they were not expected to conduct science themselves. Mabel attended as part of the domestic framework of an expedition; Elizabeth both built that framework and supported her husband. Helping a scientist might be seen as women’s work, but being the scientist was not yet possible for women who, in another era, might have performed the fieldwork themselves.