ผลต่างระหว่างรุ่นของ "ประภาคาร"

 

==แหล่งข้อมูลอื่น==

*[http://books.google.com/books?id=sygDAAAAMBAJ&pg=PA66&dq=Popular+Science+1931+plane&hl=en&ei=ESQHTd47iL2cB5fYkeYN&sa=X&oi=book_result&ct=result&resnum=9&ved=0CEIQ6AEwCDgK#v=onepage&q=Popular%20Science%201931%20plane&f=true "Lighthouses Of Strange Designs, December 1930, Popular Science]

*[http://www.lighthousefriends.com/makapu%27ulens_cga.jpg Photograph of Makapuu Point hyperradiant lens, U.S.C.G.] at lighthouse friends.