434 Sir James N. Douglass [March 15, 



gas, commnuicates motion to a lever, which, assisted by a spiral 

 spring, closes the inlet pipe, and opens at the same time the passage 

 to the burner. As the gas passes on and is consumed at the burner 

 the diaphragm, by its own weight, assisted by the springs, sinks, and, 

 touching the lever, closes the outlet aperture to the burner, and, at 

 the same moment, opens the inlet of the gas from the buoy for 

 another charge. Thus the light is extinguished while the gas is 

 entering the chamber and until the latter is re-filled, when the passage 

 from the buoy is again closed by the rising of the diaphragm. A 

 small pilot jet is constantly burning to ensure the re-ignition of the 

 gas when re-admitted to the burner. It is evident that several cha- 

 racteristic distinctions of light may be obtained by modifications of 

 this ingenious apparatus. About 150 buoys lighted on the Pintsch 

 system are already rendering valuable service to mariners in various 

 parts of the world. For the more important stations at sea, where 

 light-vessels are now employed, the system is considered to be yet 

 wantinsc in that trustworthiness which should be the leadincj cha- 

 racteristic of all coast lighting. Very important experiments have 

 lately been made by the Lighthouse Board of the United States, 

 at their general depot at Tompkiusville, New York, with buoys 

 lighted electrically by glow lamps, operated through submarine con- 

 ductors from the shore. These experiments have ju'oved so successful 

 that an installation for marking the Gedney's Channel, entrance of 

 Lower Bay, New York Harbour, with six buoys and 100 candle glow 

 lamps, was lighted on the 7th of November last. Gas buoys were 

 considered inapplicable for this special case, owing to their form 

 and size rendering them liable to break adrift, particularly when 

 struck by floating ice or passing vessels. The buoy adopted for the 

 service consists of a spar 46 feet long, having its lower end shackled 

 direct to a heavy iron sinker, resting on the bottom. At the upper 

 end the buoy is fitted with an iron cage, enclosing a heavy glass jar, 

 in which is placed the glow lamp of 100 candle units intensity. The 

 cable is secured by wire staples, in a deep groove cut in the buoy, and 

 covered by a strip of wood. For a distance of several feet at the 

 lower end of the buoy the cable is closely served with iron wire, over 

 which is wound spun yarn, to prevent injury from chafing on the 

 shackle and sinker. The central station on shore, with steam engines 

 and dynamos in duplicate, is on Sandy Hook, at a distance from the 

 extreme buoys of about three nautical miles. The installation is re- 

 ported to be working continuously and successfully. For auxiliary 

 or port lights on shore, where no collisions can occur, the Pintsch 

 gas system is found to be very perfect. At Broadness, on the Thames, 

 near Gravesend, the Trinity House erected, in 1855, an automatic 

 lighthouse illuminated on Pintsch's system, as shown by the diagram. 

 This small lighthouse shows a single flashing light, at periods of ten 

 seconds, the flashes having an intensity of 500 candle units. The 

 flashes and eclipses are produced with perfect regularity by special 

 clockwork, which alsu turns on the gas supply to the burner at 



