to Bar, and touching the weakeft, T procured in both 
of them (without the AlTiftance of either of the other 
feven) a nxed Polarity to fuch a Degree as that the 
North Pole, or unmarked End of either of them held 
downward, would attrad the North End of the Needle, 
though much fainter than if the North Pole of the 
Bar had been upward, and Pofition did not now change 
their Polarities, but only weaken them : Therefore I 
now call their Vertue perfedly permanent. Four or 
five Repetitions more encreafed their Vertue to fuch a 
Degree as that the South Pole of one of them would 
lift a Ten-penny Nail prepared, and after 2 or 3 Re- 
petitions more a common Door Key of an Iron Box- 
Lock, Weight ^roy 5j and above 3ij, not by the Bow, 
but by its lower End, which was wrought fomewhat 
globular and poliflied. In the laft Place 1 got a Piece 
of Inch Deal above three Inches broad and 7 or 8 
Feet long, in the Middle whereof, at about 5* or ^ 
Inches from one End, I made a Hole through with a 
large Gimlet, into which I drove an Iron or Steel 
Pin, whofe Length (befides what went into the Wood) 
was a little lefs than the Thicknefs of one of the Bars. 
Then I placed the biggeft Bar on the faid Board with 
its marked End clofe to the Pin, and its Length pa- 
rallel to that of the Board, and with an Awl made four 
fmall Holes in ’the Board, one of them on each Side of 
the Bar about an Inch from the Bottom, and about 
the Thicknefs of a Sixpence, from its Sides, and the 
other two after the fame Manner, about an Inch from 
the Top. I drove into them Pins of large Wire half 
an Inch long, befides what was in the Board. The 
Pins were to keep the Bars from Aiding out of their 
Places in touching* Then removing that, and placing 
a any 
