"the sole heiress and reputed daughter of Baillie Orde of Glasgow"
A baillie was a magistrate - consequently, though Lady Dalcastle’s background is respectable, the marriage would represent a social step down for the laird, were it not for his need of the heiress's fortune. Pretending an objectivity which masks his real reluctance to incriminate the party with whom he sympathises, the Editor hastily glosses over what could be viewed as an act of mercenary opportunism.
At the turn of the 18th century when the novel’s action takes place, Glasgow was burgeoning into the major city it is today. Already a significant trading centre, the establishment of Port Glasgow in 1668 meant that the city was also fast becoming a mercantile and manufacturing stronghold. In 1700, its population stood at around 12,000.