Rare Working Celestial Navigation Chart!
Rare working navigational celestial chart of the northern skies, published by the United States Hydrographic Office.
Updated to August 5, 1916, the chart was actually utilized by mariner's at sea to take readings and navigate at night.
Includes an explanation on how to use the chart (mount on light drawing board, affix pivot string, etc.), a table showing the magnitude of stars in six sizes, symbols for the planets, etc.
OCLC locates only a photo copy of these charts -- no other recorded examples.
These charts are very rare on the market.