M AG N i: T I c S D i: v i: V F P E X N S V I, V A XI \ . 



Irwin's Mill, near Mcrcersburg, Pa. — Ten miles from Clear Spring, Md., and six miles 

 from Mercersburg. Field (limi o X. W. 



Temp. Fahr. No. of series. 



X., of 



vibrations. 



Aug. _ 1 Noon Cylinder 

 " " 2" V. M. Bar 



78°.5 

 76.0 

 92.0 



lco 

 1G0 



Time of 

 10 vibrations 



i'..ii .1. 



Horizontal 



illtrll-ll V 



Phil. 1 0000 



34'. 45 

 34. I.". 

 36.62 



34".419 1.0068 

 34.419 1.0068 



36. 182 



temp, doubtful 



.Mean 



| n, 68 



Cumuli, wind brisk. 



An-, 24 



No. 1 

 X... :; 



Dip. 



71° 50'. 5 

 71 34.2 



Temp. Fiihr. Dip when loaded. 



81°.0 

 81.5 



17° 27'.3 

 19 41.5 



Dip reduced. 



Relative total 

 intensity. 



71° 41'/. 1 

 71 41.5 



1.1745 

 L.1948 



Mean 



71 43.S 



l.lsn 



Baltimore. — Second square X". E. from Washington Monument. 





Aug. 27 



Temp. Fahr. No. ol 



No. "f 

 vibrations. 



Time "f 

 10 vibrations. 



Corr'd. 



Bar 

 Bar 



71°.5 

 71.0 



150 

 150 



3G 8 .39 

 36.39 



36 s . 342 

 36.342 



Horizontal 

 intensity 



Phil. 1.0000. 



1.0252 

 1.0252 



Mean 



1.02.V2 



I lazy, wind brisk. 



Date. 



Time. 



Aug. 27 



Xo. 1 

 No. 3 



Dip. 



71° 37M 



71 22.ii 



I'.ihr. 



Dip when loaded. 



Dip reduced. 

 t 



16' 



19 



Mean 



:>i;'.:; 



(IS ., 



71° 32'. 7 

 71 29.3 



71 31.0 



Relative total 

 Intensity. 



t.1736 

 1.1933 



1.1834 



