[ 5°9 ] 
would be more in the Direction of the Earth’s Mag- 
netifm than before ; on which account it would ad 
ftronger in retaining the Needle in that Situation, 
than the Stream of the other Side in reftoring it j 
cfpecially as that Stream would be now weaker, on 
account of its being turned out of the magneticai 
Line, and would have the Fridion betwixt the Cap 
and Pin to overcome at the fame time. 
I tried two other Needles, whofc Ends were 
formed into Angles very obtufe, and .could not find 
that they were liable to the fame Objedion. 
Two Needles that were quite ftrait, and fquare at - 
the Ends, were found to have only two Poles 5 but 
about the Hole in the Middle the Curves were a lit- 
tle confufcd. Thcfe always came cxadly to the 
fame Point, after vibrating a long time; and if 
drawn never fo little on one Side, woii'id return to 
it again without any fcnfible Difference. We may 
therefore conclude, that a regular Parallclopipcd is 
the beft Shape for a Needle, as well as the fimplcft ; 
with the Holes for the Caps as fmall as can well be 
contrived; or if it can be made to anfwer the Pur- 
pofe without any Hole at all, it will be dill more 
perfed. 
Yet the common Shape has one Advantage which 
this has not: For, being made broad at the Ends, 
and (lender in the Middle, its Weight is removed as 
far as pollible from the Centre : On which account, 
if it once points true, the Fridion at the Centre 
cannot fo cafily put it in Motion ; and its Vibra- 
tions, when in Motion, wiil be flower ; fo that 
their Limits may be more nicely obferved, and the 
middle Point betwixt them is that where it would 
T 1 1 2 ftand. 
