The question is why do iron-hulled naval ships have a brass plaque recording the location and orientation?

Question

This is a question from a Conceptual Physics course I am taking and this question is from a chapter dealing with Electricity and magnetism.

Answer 1

Of their manufacture? During welding, some of the metal on a ship will remagnetize in the Earth's magnetic field. This will throw off their compass, so such a plaque will help the ship's navigator adjust the compass.

Answer 2

When a metal ship (or a wood ship with cannon, anchors, etc.) is using a magnetic compass, one of the things that has to be done during fitting out or refitting is to take it out to a range, anchor it, and turn it to point at various points of the compass. These are recorded in detail and a brass plate is etched to show the adjustments that need to be made to the compass when the ship is heading N, E, S, & W as well as selected points in between. Brass does not affect the compass. These corrections are added to those from a map or table giving the variations in the compass due to local anomolies and the fact that the magnetic poles are several hundred miles from the axis poles of the earth.

Answer 3

Brass is non-magnetic. The direction a compass points within an iron or steel enclosure will be affected by the surrounding steel. The brass plate provides an orientation for the compass adjusted so that the compass needle points North on the compass bezel when the vessel is pointing North.

Answer 4

a brass monkey became into infact the a three legged brass stand which had 3 holes wherein held 3 cannon balls , those have been on the previous crusing ships with cannons, the form looked like a monkey, whilst it became into warm , the brass expand, whilst it became into chilly the brass could settlement, inflicting the holes to in the braass monkey to cut back and start to p.c. up , forcing the balls to come again lose and fall off the brass monkey, rolling around the ships deck for this reason it is chilly adequate to freeze the balls of a brass monkey or the shortened term is brass monkey climate (the postman became into being well mannered)

Answer 5

I'm guessing that it is simply a traditional thing , buddy.