OPTICAL TELEGRAPHY. 
23 
the Morse code to distinguish each ship would be highly useful, 
either for naval manoeuvres, or for corresponding with ports 
at a distance, and also for the avoidance of those dreadful 
collisions which are only too frequent. 
It appears, then, that whether for telegraphing, or for light¬ 
houses, or for ships, the employment of intermittent signals 
will become indispensable ; and that by the help of movable 
screens, such as are now used in military telegraphy, they can 
easily be produced without any practical inconvenience. 
