Democratic Sentinel, Volume 17, Number 41, Rensselaer, Jasper County, 27 October 1893 — “Lines of No Variation.” [ARTICLE]

“Lines of No Variation.”

In my recent article on the variations of tbecoinpass I find that one important particular was omitted, viz.: Mention of the fact that there are certain places on the earth’s surface whieh are situated upon what the astronomers call “line of no variation.” At present this line passes near Wilmington, N. C., Charlotteville, Va., and Pittsburg, Pa. On the eastern side of this remarkable invisible line the variation of the needle is toward the west, increasing with the distance the compass is removed from it. Thus we find that at New York City the variation is six degrees west, and at Portland, Me., it is 12 degrees in the same direction - On the other side of this ■•line of no variation” the declination is, of course, toward the east, varying from 1 to 20 degrees between Pittsburg and San Francisco, depending on the longitude of the place of observation. This variation undergoes what is technically said to be a “progressive change.” always vibrating between certain limits. In the Eastern States (States east of the “line of uo variation”) this progressive change to the westward is at the rate of about one degree in every 12 years. [St. Louis Republic.