Note 157 — Chapter I

Humboldt, Examen critique, iii. 54; Cosmos, v. 55. Columbus found this point of no-variation, Sept. 13, 1492. In the latter part of the sixteenth century, for a similar reason, St. Michael’s in the Azores was taken for the first meridian, but the no-variation then observable at that point has given place now to a declination of twenty-five degrees.