[ 66o ] ' 
The two needles were then themfelves applied to 
each other, firft the northern half of the one, in a con- 
trary dire&ion, to the northern half of the other j and 
then the fouthern half of the firft, in a like contrary di- 
rection to the fouthern half of the laft ; and from thefe 
feveral pofitions, they were feverally drawn till they 
were clear of each other, and this feveral times fuc- 
ceflively: after which operation it was found, that the 
tempered needle had loft fo far its virtue, that its 
northern end had hardly any effeft upon the needle 
in the box 5 that its fouthern end even began -to at- 
traft the contrary end of the needle from what it 
did before, and that it was no longer able to lift 
at either of its ends any fenfible weight. 
But as to the hard needle, that ftill* retained a 
confiderable {hare of its former virtue; its ends ftill 
ftronglv drawing the fame ends of the needle in the 
compafs-box as they drew before, and either of them 
lifting with eafe the heavier of the two above-men- 
tioned weights. 
Mr. Knight then produced one of his common 
fmall magnetic bars; the which being applied to the 
forementioned large bars, in the fame manner as 
the needles had been applied to the fame, but in a 
pofition contrary to that of its prelent polarity , it 
had its poles thereby counterchanged or inverted, 
and was found to lift at that which was now become 
its northern end, the weight of 6 ounces 8 penny- 
weight and y grains. 
He laftly produced one of his large artificial 
armed magnets, compoled of feveral thin plates 
offteel cramped together, with which he acquainted 
us he had fome time before lilted 3 6 pounds, 
and 
