There is but one day in the year when the phenomenon of the midnight sun can be seen at the imaginary line which we designate as the Arctic Circle, a point twenty-three degrees and twenty-eight minutes from the North Pole; but by sailing some three hundred miles farther northward to the North Cape, the projecting point of the extreme north of Norway, it may be observed under favorable circumstances,-that is, when not obscured by clouds,-for over two months dating from the middle of May.
"Due North or Glimpses of Scandinavia and Russia"
Maturin M. Ballou
It is measured by the angle one of whose sides is an imaginary line drawn to the center of the earth and the other of whose sides is an imaginary line passing from the center of the earth into the celestial sphere through the center of the heavenly body whose declination you desire.
"Lectures in Navigation"
Ernest Gallaudet Draper
This imaginary spot held for me the revealing of no great scientific secrets.
"My Attainment of the Pole"
Frederick A. Cook