Answer: They are measuring Winthrop's robe
Step-by-step explanation:
The Scarlet Letter by Nathaniel Hawthorne is describing a romance that is a work of historical fiction. They are out at midnight because they were going to measure robe of Governor Winthrop and later, they are out at midnight because Hester wants to watch his death bed. This romance was published in the 1850s and it was very popular.