Annual report of the United States Geological Survey to the Secretary of the Interior . FlG. i.—Diagrams of secular variation in northern United Slates and at Paris. northern United States, both of them constructed upon the same diagram illustrates the rapid llatteningof the curve as the latitude. GANNETT.] THE COUNTY TABLE OF RESULTS. 305 diminishes, Paris being in latitude 48° 57, while the mid-latitude ofthis part of the United States is seven or eight degrees less. Assuming that the secular change is due to an eastand-west move-ment of the supposed north magnetic pole, it would a
Annual report of the United States Geological Survey to the Secretary of the Interior . FlG. i.—Diagrams of secular variation in northern United Slates and at Paris. northern United States, both of them constructed upon the same diagram illustrates the rapid llatteningof the curve as the latitude. GANNETT.] THE COUNTY TABLE OF RESULTS. 305 diminishes, Paris being in latitude 48° 57, while the mid-latitude ofthis part of the United States is seven or eight degrees less. Assuming that the secular change is due to an eastand-west move-ment of the supposed north magnetic pole, it would appear that theeffect of this shifting of the pole diminishes southward, becoming, per-haps, zero at the magnetic equator. THE COLTNTY TABLE OF RESULTS. The following table presents in what is believed to be a compact andconvenient form for use the results of this compilation and results are given in the form of the mean declination of each countyin which observations for declination have been obtained. In countiesin which no declinations have been obtained the declination of the year1900 has been estimated from adjoining counties, as is indicated in thetable. In addition to this, the declination is given at each town or citywithin the county at which such observations have been obt
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