Back in the days before two-way radios and sirens–not to mention organized police forces–night watchmen on the beat had to carry something to alert others if they needed assistance. Something relatively small that they could carry on their person, something easy to operate, and something really loud and distinctive.
And that’s the answer to today’s mystery artifact. This early 19th century watchman’s rattle would be whipped out in case of emergencies and spun rapidly around. The wooden clackers would ideally alert other watchmen in the vicinity, wake up the villagers, and perhaps even scare off criminals.