Gathering at Lord Darlington's house after going out, the men discuss Mrs. Erlynne, women, and marriage through their characteristic combination of banter, teasing, and aphorisms. Using an idiom, Dumby claims that women are willing to sacrifice their own virtue for commercial motives:
Awfully commercial, women nowadays. Our grandmothers threw their caps over the mills, of course, but, by Jove, their granddaughters only throw their caps over mills that can raise the wind for them.
Here, Dumby plays with the idiom "to throw one's cap over a windmill," which is used to describe someone who behaves in conflict with social conventions. This comes from the Spanish epic novel Don Quixote by Miguel de Cervantes, which features a story in which the titular main character mistakes windmills for giants. In order to challenge them, he throws his hat over the windmills. Someone who throws their cap over a windmill is thus someone who behaves in an irrational and reckless way.
The idiom is occasionally used to describe promiscuous women. Based on older standards of dress, a woman who acted in line with etiquette would usually keep her cap on in public. This is because concealing her hair showed that she was modest and virtuous. Conversely, if a woman was willing to throw her bonnet or cap over a mill, she would have been renouncing her regard for conventions.
Dumby adds something to this idiom, saying that women today "only throw their caps over mills that can raise the wind for them." Through the idea of the mill "raising the wind," Dumby suggests that women of the late nineteenth century have a specific scheme in mind when they behave in contrast with societal expectations. In his view, although women of a few generations ago could certainly be reckless and promiscuous, women of the current generation have economic motives in mind when they seek extramarital relationships.
There is perhaps some truth to his statement, particularly as it pertains to women's limited options for seeking financial security. At the end of the nineteenth century, it was still much harder for women than men to make money of their own. Pursuing a rich man was one of the surest ways for a woman to elevate her quality of life or to increase the material comforts she had access to. Whether as a daughter, wife, or mistress, women in Victorian society were usually more financially secure when they were linked to a wealthy man. A character like Mrs. Erlynne seems like she would prefer to make her own money and cultivate her own good reputation, but marrying Lord Augustus serves as the most straightforward path to achieving these goals.
