EXPLORATIONS ACEOSS THE GREAT BASIN OF UTAH. 



(Mirror below :) 



Limb of magnetometer reads, first vertical. 



Grand mean of magnetic south poii 



True south point reads, first vertical, — 

 True south point reads, second vertical . 



Difference of mean readings or magnetic azimuth 11° 59' 15 E. 



Lieut. H. S. Putnam, Observer. 



Note.— In the above case the true meridian had been determined by an observation on Alioth («, Ursw Majoris) and 

 Polaris, and marked on the ground. In our observations on the march the magnetic azimuth of the sun was observed 

 and the true azimuth (or meridian) determined from the known I .nation. 



