Pelorus - Technical instrument - United Kingdom - 1850-1900

Pelorus navigational brass instrument from the late 19th century

Circa 15.2 cm diameter
Pelorus, a navigational instrument that was used aboard ships to take bearings relative to the ship or north. The specimen in the photo is made of brass and is presumably dated to the end of the 19th century or the early 20th century.
Features and Origin

Function: A Pelorus works like a 'blind compass'. It has no own magnetic needle, but is manually aligned with the ship's compass. With the aid of a sighting device (which was originally mounted on the central hole) the navigator could determine the angle to objects on shore or other ships.
Markings:
The disk is equipped with a degree scale (0-360) along the edge.
The letters 'N' (North) and 'S' (South) indicate orientation.
The inscription 'Latitude' with a corresponding scale suggests that this specific component could also be used for astronomical calculations or settings based on latitude.
Style: The ornate engraving on the underside (the crescent-shaped decoration) is characteristic of scientific instruments from the late Victorian period or the early 20th century.