1920] 



on The Gyrostatic Compass 



21 



The ship's magnetism may quickly change through the hammer- 

 ing" action of the waves, or the heating action of the sun on one 

 side of the vessel, or through an earth on any of the electric wires 

 that may be running near the compass ; all these things together 

 add to the anxiety of the captain, as he is never quite certain how 

 far the compass is correct in its readings. The swings of the modern 



Fig. 1. — Gyro-Compass in Binnacle. 



compass are damped by immersing the needles and card in a liquid 

 such as alcohol, but as this fluid is attached to the ship and turns 

 with it. swinging the ship in any direction carries the liquid round 

 and re-acts on the needle and card, so that the compass has a 

 tendency to be carried round with the vessel. 



