Mr. Sidney G. Brown [Jan. 30, 



the same air box K are the two damping bottles CC, smaller than EE, 

 but the air here acts in the opposite direction to that in the left- 

 hand side of the figure. 



In <>nc of these damping bottles is the adjustable needle valve, 

 and this valve has a constricted passage, and thus the flow of oil 

 from one bottle to the other is suitably retarded. 



As regards the accuracy of the compass, I may mention that one 

 on board a flagship in the North Sea during the War was observed 

 with particular care, especially during very heavy weather, and it was 

 reported that it was never more than 1 J° from the true north position 

 during the whole of the tests. 



Trials on a commercial ship have demonstrated the fact that the 

 employment of a Gyro-Compass resulted in the ship steaming every 

 day over 3 per cent greater mileage ; in other words, 1 day's 

 steaming in 30 would be saved, resulting in a proportionate saving 

 in coal and all other expenses. 



I come now to a most important application of the Gyro- 

 Compass — namely, its employment as a gun director. 



The use of the gyrostat in the Whitehead torpedo has revolu- 

 tionized naval strategy, and I believe the use of the same instrument 

 in the form of a Gyro-Compass gun - director may possibly produce 

 profound changes in gunnery practice in the future. 



Modern naval warfare is entirely different to that of the past in 

 the fact that the rival fleets come into action when separated by 

 many miles. The guns have therefore to be worked and tired while 

 the distant targets are invisible to the gunners. 



The guns have to be directed by observers in an elevated 

 position, these observers communicating the distance of the target 

 and its direction in space. 



The direction in space must be supplied by a Gyro-Compass on 

 board the ship, and it is essential that the compass for this purpose 

 be of extreme accuracy. 



Once the guns are properly trained they may be joined up and 

 be controlled by the Gyro-Compass, and for this purpose the turrets 

 would be designed to act as huge repeaters, keeping the guns 

 pointing on the target, changing only on receiving new directions 

 from the observer. 



The compass would hold the guns pointing on the distant target 

 quite independent of the movements of the ship, which may at the 

 time be steaming at full speed and manoeuvring. Such movements 

 are a great protection to ships against submarine and aerial attack. 



It has been suggested that the day of the great battleship is over, 

 but I am doubtful of this, as I understand that ships can be made 

 proof against ordinary submarine attack by means of blisters filled 

 with oil, as in our Navy, or by coal dust, as used by the Germans. 



Working the guns with the ships at full speed, as J have just 

 stated, will be an additional protection, while submarine craft will be 



