In the North Atlantic during the summer months Vega, Deneb or altair in the East, Antares or Deneb Kaitos in the South, Arcturus in the West, and Polaris, Mizar, or Kochab in the North form an ideal combination which includes every quadrant of the compass.
"Lectures in Navigation"
Ernest Gallaudet Draper
When it is at 4 it is at eastern elongation, and altair is near the meridian.
"A Text-Book of Astronomy"
George C. Comstock
The last constellation which we shall here describe is that of Aquila or the Eagle, which contains a star of the first magnitude, known as altair; this group can be readily found by a line from Vega over b Cygni, which passes near the line of three stars, forming the characteristic part of the Eagle.
"The Story of the Heavens"
Robert Stawell Ball