NAVIGATION AND SAFETY AT SEA 



19 



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^",/>'°. 



HO. PUB. NO. 229 



SIGHT REDUCTION TABLES 



FOR 



MARINE NAVIGATION 



LATITUDES 75°-90°. INCLUSIVE 



The latest in navigation tables. 



Accordingly, the Navy, in collaboration with H. M. Nautical 

 Almanac Office of Great Britain, is participating in the production 

 of a newly-designed, newly-computed set of tables intended as a 

 replacement for H. O. Pub. No. 214. The new Sight Reduction 

 Tables for Marine Navigation, to be indentified as H. O. Pub. No. 

 229, will facilitate the practice of astronomical navigation at sea, 

 to the highest precision possible by conventional methods of 

 observation and altitude correction. Since many years will pass 

 before even the majority of ships are fully equipped with automatic 

 position-fixing systems, these new tables will meet a vital national 

 and international need of navigators for many years to come. 



Of the tables issued by the Navy for use with electronic position- 

 fixing systems, the Loran Tables of the H. O. Pub. No. 221 Series 

 are best known and most widely used. Familiar to nearly all 

 ships of the Navy and merchant marine, the tables provide the 

 mariner with charting coordinates for hyperbolic lines of position 



