C 479 ] 



Experiments made April 22, 1772, with the other 

 Dipping-needle, the inftrument being put in the 

 fame place, and with great care, in the magnetic 

 meridian, the needle pointed as under. 



72 15 



72 10 The poles of the needle changed. 



{The fide of the inftrument to the 

 Eafl, which in the firft obfervation 

 was to the Weft. 



Left any thing magnetical mould have affected the 

 needle in Mr. Nairne's houfe, he took this inftru- 

 ment, and placed it in the middle of a large room 

 belonging to the London AfTurance in Birchin- 

 Lane, and then the needle pointed to 



72 10 or 15 



72 20 



72 30 The poles of the needle changed, 



{The fide of the inftrument to the Eaft, 

 which in the firft obfervation was to 

 the Weft. 



The dipping-needle brought back to Mr. Edward 

 Nairne's, and put in the fame place as before, 

 ftood at 



o r 



72 IO + 



The 



