chronometers by the proximity of masses of iron. 385 
1st. If the balance have a polar, or directive quality, and 
the iron is pure and free from it (except that which is due 
to position) ; then, if the balance be kept below the plane of 
no attraction , the south pole of the former will be attracted, 
and its north pole repelled ; but if the balance be placed above 
the plane of no attraction, the reverse will take place ; that 
is to say, that part of the balance which was before repelled 
will be attracted, and that which was attracted will be re- 
pelled ; and the same will happen, whichever of the ends or 
parts of the iron be turned downwards. 
Therefore, when such action as that above described takes 
place, we may infer that the balance is magnetic, but that 
the iron, or attracting mass, is free from any polar quality, 
except that which it derives from position. 
2. If the iron and balance were both magnetic, then we 
should have attraction and repulsion, as above described ; but 
it would have no reference to the plane of no attraction ; and 
by inverting the position of the iron, the effects of it upon 
the balance would be reversed also. 
3. Again ; if the iron possess the polar quality, but the 
balance and spring are free from it, then in every situation, 
either side or part of the balance, which is nearest to one of 
the poles of the attracting body, will be attracted, and no 
repulsion will in such case be observed. 
4. Lastly ; I am of opinion (although it is here, as in most 
other cases, difficult to prove a negative) that no action what- 
ever will take place between the balance and iron, provided 
they are both free from any fixed polar quality. 
As we were not prepared to pursue our enquiries any far- 
ther at this time, Mr. Frodsham proposed to provide himself 
