THS COLUMBIA RIVEiR LIGHT VE;SSe;l, AFTER BKING STRANDED ON CAPE DISAPPOINT- 

 MENT IN 1899, WAS HAULED THROUGH THE WOODS 7OO YARDS AND 

 LAUNCHED INTO THE RIVER (SEE PAGE 43) 



BUOYS 



Floating buoys are efficient and rela- 

 tively inexpensive aids to navigation. 

 They are used to mark dangers — as 

 shoals, rocks, or wrecks — to indicate the 

 limits of navigable channels, or to show 

 the approach to a channel. They vary 

 in character according to their purpose 

 or the distance at which they should be 

 seen. The simpler forms are the wooden 

 and iron spar buoys, and iron can and 

 nun buoys. For warning in thick 

 weather, buoys are fitted with bells, 

 whistles, and submarine bells, all actu- 

 ated by the motion of the sea. 



Some important buoys are lighted, 

 usually by means of oil gas compressed 

 in the buoy itself or acetylene gas com- 

 pressed in tanks placed in the buoy or 

 generated in it. The light is often flash- 

 ing or occulting, for the purpose both of 

 providing a distinctive mark and of pro- 



longing the supply of gas. The use of 

 gas buoys has greatly increased in recent 

 years, there being at present 346 in this 

 country. They are a very valuable addi- 

 tion to the aids for the benefit of mari- 

 ners, and often obviate the necessity of 

 establishing much more expensive light 

 vessels or range lights on shore. 



The buoy off the entrance to Ambrose 

 Channel, New York harbor, at a height 

 of 27 feet above the water, shows a light 

 of 810 candle power, occulting every 10 

 seconds and visible 10 miles. This buoy 

 recently burned for one year and four 

 months without, recharging. The buoy 

 is nearly 60 feet long and weighs over 

 17 tons (see page 50). 



Buoys are painted and numbered to 

 indicate their position and the side on 

 which they should be passed. To keep 

 the 6,700' buoys of this country on their 

 proper stations and in good order is a 

 heavy work and is one of the principal 



46 



