296 LIGHT SCIENCE FOR LEISURE HOURS. 



PORT SIDE LIGHTS. 



K a W 



STARBOARD SIDE LIGHTS. 



W a K 



(W a powerful -white light at the bow, R a powerful coloured light 

 at the stem, W only visible when the bow is nearer than the stern to 

 observer, R only visible when the stern is nearer to observer than the 

 bow ; a b c the midship port lights arranged in the form of an equi- 

 lateral triangle. 



A little consideration will show that, if such lights 

 were used, not only would the port side be distinguished 

 as now and from the starboard one much more quickly, 

 because white lights are seen much farther than 

 coloured ones, but the exact bearing of the ship's 

 midships would be at once shown by the foreshortened 



shape of the triangle a b c. 



Newcastk Weekly Chronicle. 



