The Friends of the Mattapoisett Library will be holding its used book sale during Harbor Days. The sale will take place on Friday, July 19, and Saturday, July 20, from 10:00 am until 2:00 pm at the Library, 7 Barstow Street. A members-only preview will take place on Thursday, July 18, from 3:00 pm until 5:00 pm.. Come in out of the heat of the weekend and browse the large collection of adult and children’s books.