( U 7 ) 
equal , and the ycth Degree to be perpendicu- 
larly under the Axis of the Needle ; this laft 
I found was a little faulty , the T)ip being in 
Reality greater than the Semicircle f jewed it. 
After I had rectified this Error , and new touch'd 
the Needle , upon that Part of the Armour to which 
Iron is applied , when it is to be lifted by the 
Stone , it perform’d the fame Number of Vibra- 
tions in lefs Time than in any of the former 
Trials . I now determin'd to obferve , for fome 
Space of Time , both the Dip and Vibrations , with- 
out frejh touching the Needle . 
The Obfervations follow, by which it appears there 
is a very confiderable Difference, both in the Quanti- 
ty of the Dip , and in the Quicknefs of the Vi- 
brations, 
N.B. In all thefe Experiments , the Needle was placed , 
fo as to vibrate exaBly in the Plane of the Mag- 
netick Meridian \ and fufficiently dijlant from all 
Iron that could affeTt it , as far as 1 could per- 
ceive , till I had Occafwn to put up a very large 
Iron Rod in the Room above it , which immediately 
alter'd the Dip of the Needle , and thereby put an 
End to thefe Trials . 
Dip 
