People newly appointed to post tend to make big changes. Like new brooms, they do their work thoroughly.
When Mrs Bristow retired, Miss Parsons was appointed superintendent of the department. She found fault with all Mrs Bristow’s methods, which she described as old–fashioned, and turned the department upside down, much to the annoyance of the girls who had worked so happily under Mrs Bristow. Little wonder they muttered among themselves about new brooms!