THE COUUxMJ'.IA LIGHT VESSEL JOURXEVIXG THROUGH 

 THE WOODS 



uses for the lighthouse tenders. Buoys 

 may be damaged or sunk, or dragged or 

 broken from their moorings by vessels 

 or tows, or wreckage, or ice. 



Two buoys from the Atlantic coast of 

 this country have been picked up on the 

 coast of Ireland, and one from the Cali- 

 fornia coast was found in the Hawaiian 

 Islands, these having gotten adrift and 

 been carried across the oceans by the 

 currents. 



For use in mooring buoys and light 

 vessels, the Lighthouse Service purchases 

 annually about 15,000 fathoms of chain, 

 a length equal to 17 statute miles. 



roc SIGNALS 



The most powerful coast lights may 

 be rendered of little or no use to navi- 

 gation by thick fog or rain. To assist 

 vessels under such conditions, making 



their course more safe or allowing them 

 to proceed, fog signals of many sorts 

 have been established. Of these the bell 

 is the most common, and until about 

 1850 the only signals in use were bells 

 and guns. The first fog signal on the 

 Pacific coast of the United States was 

 established at Bonita Point. San Fran- 

 cisco Bay, in 1856 — a fog gun to be fired 

 each half hour. 



The fog signals now in use in the 

 United States consist of sirens, whistles, 

 reed trum])ets. aerial bells, and submarine 

 bells. Sirens and whistles are operated 

 by compressed air or steam, and trum- 

 pets by compressed air. To furnish air, 

 compressors driven by internal com- 

 bustion engines are used, and for steam 

 signals boilers are employed. The larger 

 fog bells, uj) to 4,000 jKjunds, have ham- 

 mers actuated by a weight and clock- 



47 



