102 MARINE LIGHTING EQUIPMENT OF THE PANAMA CANAL, 



lighting. Burned in a self-luminous burner without the use of a mantle the 

 flame of acetylene gives an intensely concentrated white light, comparable 

 only to sunlight. The illuminating power of pure acetylene is five times 

 that of the richest oil-gas, and its efficiency remains unchanged by compres- 

 sion. For buoy lighting acetylene must be perfectly dry and of absolute 

 purity. As generated from ordinary commercial carbide, it contains moisture 

 and impurities which, if not removed, would rapidly clog the flashing mechan- 

 ism or carbonize the burner. The earliest type of buoy using acetylene as 

 an illuminant is the " carbide buoy," a Canadian invention, in which calcium 

 carbide is stored in a receptacle having free access to the surrounding water. 

 This buoy has the objection previously cited, namely, that the gas thus 

 generated is not dry nor sufficiently purified for the proper and continuous 

 functioning of the burner and flasher. This fault, combined with its inherent 

 wastefulness, has gradually led to the abandonment of the carbide buoy in 

 favor of the simpler and more efficient type, using dissolved acetylene, and 

 now adopted for lighting the Panama Canal. 



DESCRIPTION OF THE SYSTEM ADOPTED. 



Beginning with its introduction to this country in 1908, this system 

 (Dalen patents) has made such steady progress that to-day it is installed 

 in over three hundred important light-stations of the United States and 

 possessions. 



To cite a few examples near home: — ^Ambrose Channel, the gateway of 

 ocean commerce to New York, is marked by large buoys equipped with 

 powerful, rapid-flashing lights visible at a range of over twelve nautical miles. 

 The Delaware River channel to Philadelphia is lighted by beacons and range 

 lights, from the light-vessel No. 44 off Cape May to the Horse-Shoe buoy 

 and ranges at League Island. 



Space will not permit of further enumerating the various channels, 

 harbors, etc., lighted by this system, which will now be described in its 

 application to the lighting of the Panama Canal. 



THE BUOYS FOR THE PANAMA CANAI,. 



Plate 47 is a plan and elevation of the Panama buoy, in which A is the 

 cylindrical body or chamber, 8 feet in diameter, made of A-inch steel plate 

 with dished heads riveted on. Through the center of the body passes the 

 tube B, to which is bolted the counterweight C. This tube is made in two 

 pieces, as indicated at D, for convenience in ocean transportation. The 

 pyramidal skeleton tower E is bolted to the cast steel foot-brackets F, and 



