3IO M E M O I R S of tl)e 
very vigorous in this their polarity, others fhewed plainly a ten- 
dency to one 'Poky rather than the other, yet lb faintly, that they 
applied contrary to their inclination, that is at the upper end, if 
they affe£ted to draw the fouth, or at the lower end, if the north,. 
by caufing the needle to iland in JEqullibrio, eafl and weft, the 
particular inclination of one end feemed in fome pieces quite to 
conquer, in others quite to hinder that more general polarity, 
they both acquire by being either upwards or downwards, yet this 
feems to be found only in fmall ftems of iron 5 they being up- 
wards or downwards always prevailing in pieces of great bulk. 
3. He took hi? knife which had been touched a quarter of a year 
or more and profc. ing ir t^ xh'^. needle, it drew the north jPo/^, 
which happened ; ight for his purpole j he whetted it brilkly on 
a di-y diity thLeHiold, and bt mg thin, i became very hot to- 
wards the point, the edge being whetted away to a wire, as they 
term it, he flriick the very top and back toward^ the top againft 
the ground, as he hid done the fides, to deftroy and rub oflE if 
he cojild, all the fi^iiier pc.'arity, wiiich was Ibutbward; then 
offering it again to the needle, it drew the fouth end and was 
quite changed 5 to confirm fhe thinj:^, he touched the lame knife 
again with rhe North 'Pole oi his ir^aHone and it drew vigo- 
roufly the north end of the needle j iie whetted it again ilrongly in 
the lame manner, and it changed again; this he repeated five or 
fix times, and it ftill changed by whetting, efpecially on the fides 
towards the top of the knife, the very top and back, which could 
not be whet to fo great a heat, retaining ftiU lome affedion for that 
'Pok the loid-ftone had inclined them ro ; this he tried with a 
knife of a thicker blade, bat could not whet it with his hand to 
that heat, lb as to have the fame eflfecl:, as upon his own knife, 
tho' he ufed fuch force as At laft to break it in two. 4. He fup- 
poles that bare drilling might be able to give a polarity to a drill, 
if it could be made indifferent, as well as filing does, and if the 
drill be uled fo brifldy as to be made as hot as the file makes the 
iron, and tho' a South 'Pole given by the magnet cannot be taken 
off by the heat of a brifk motion, as that of drilling, which yet 
by the experiment of his knife feems to be contifadidted ; yet 
perhaps the heat may be great enough to produce a polarity in an 
indifferent piece of iron, as may be done in little indifferent 
drill-like pieces of Iteel, by filing. 
J Mi- 
