Location of the Isogonic Lines. 



10,3 



the isogonic lines is in one sense attributable to "local attraction.' 

 In other words, the isogonic line — as traced — is the resultant declin- 

 ation element of the magnetic force, a figure which represents the 

 influence of the solar energy controlled by atmospheric, aqueous and 

 mineral matter in conjunction with central terrestrial forces. 



Local attraction, however, as commonly understood, is a much 

 more simple matter. Wing usually some large deflection of the com- 

 pass needle caused by the presence of magnetic iron. The lines cross- 

 ing the famous iron-dam of the upper Hudson at Adirondack, is a 

 remarkable example of this kind. I here located a meridian line and 

 at short distances along it took magnetic readings and found that 

 if this true meridian line were to be platted by the bearings of the 

 compass, the magnetic (and false) representation would be a reversed 



to exist in the magnetic 

 preserve them and render 



■ be found, so as to be re- 

 it system then becomes gh 



If this work be well done, and a thorough system of records made, 

 he ownership of property will be placed upon a substantial basis, 



nd valuable scientific data obtained which will be in the future a 

 leans of still more closely investigating the interesting phenomena 

 r e have considered, and may be the means of revealing secrets of elec- 



