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AMERICAN JOURNAL OF SCIENCE. 
[THIRD SERIES.] 
Art. XXII.—On a Chart of the Magnetic Declination in_the 
United States, constructed, by J. E. H1~earp, Assistant U. 8. 
Coast and Geodetic Survey. With Plate V. 
[From the United States Coast Survey Report for 1876.] 
Sir: I submit to you herewith, for publication in the Coast 
Survey Report for 1876, a chart of the magnetic variation in 
the United States. This chart, which shows the lines of equal 
magnetic declination (so-called Isogonie lines) for the year 
1875, is mainly based upon the observations made during the 
progress of the coast survey up to 1877, together with those 
made under my personal direction during the period 1872-77, 
at the charge of the fund bequeathed for scientific research by 
the late Professor Alexander Dallas Bache, held in trust by the 
National Academy of Sciences. f : 
When the income of this fund became available for its 
investigation of terrestrial magnetism in the United States, that 
subject being one in which Professor Bache had taken much 
its prosecution on the part of the government. The board of 
direction having approved of my proposition, an allotment was 
made for several years in succession, and the observations were 
prosecuted under my immediate direction by observers whom . 
Am. Jour, So1.—Tarep Senrts, Vor. XIX, No. 111.—Maxcs, 1880. 
