Page:Popular Science Monthly Volume 92.djvu/287

 Preparing Itself for Commercial Domination of the Air

���most directly between New York and San Francisco is the Woodrow Wilson Air Highway. Branch air highways connect all principal cities of the country. Will this map be a network of lines in a few years, with commercial air- planes flying at two thousand feet, great express machines flying at four thou- sand feet and military and police planes flying at about six thousand feet?

��271

�� �