A nocturnal as costume jewellery. This is a functioning nocturnal, though only about 5 cm tall. It shows the month ring on the outside in brass. The silver coloured inner disk shows the time and has an indicator on one edge. By setting the indicator to the month and day (in this case, a few days into October), centring Polaris in the hole in the middle and rotating the pointer attached to the centre to a specified circumpolar star, the arm indicates the time (in this case, 8 pm).