244 Dr. Faraday on Magnetic and Diamagnetic Action. 
masses which form the crust of this our globe may have an ex- 
cess of diamagnetic power and act accordingly. 
2449. Though the general. disposition of the magnetic curves 
which permeate and surround our globe resemble those of a very 
short magnet, and therefore give lines of force rapidly diverging 
in their general form, yet the magnitude of the system prevents 
us from observing any diminution of their power within small 
limits ; so that probably any attempt on the surface of the earth 
to chassite the tendency of matter to pass from stronger to weaker 
places of action would fail. Theoretically, however, and at first 
sight, 1 think a pound of bismuth or of water, estimated at the 
equator, where the magnetic needle does not dip, ought to weigh 
less when taken into latitudes where the dip is considerable ; 
whilst a pound of iron, nickel, or cobalt, ought, under the same 
change of circumstances, to weigh more. If such should really 
prove to. be the case, then a ball of iron and another of bismuth, 
attached to the ends of a delicate balance beam, should cause 
that beam to take different inclinations on different parts of the 
surface of the earth ; and it does not seem quite impossible that an 
instrument to measure one of the conditions of terrestrial mag: 
netic force might be constructed on such a principle. 
2450. If one might~ speculate upon the effect of the vinci 
system. of curves upon very large masses, and these masses were 
in plates or rings, then they would, according to analogy with 
the magnetic field, place themselves equatorially. If Saturn were 
a magnet as the earth is, and his ring composed of diamagnetic 
substances, the tendency of the magnetic forces would be. 
place it in the position which it actually has. 
2451. It is a curious sight to see a piece of wood, or of reef 
or an apple, or a bottle of water repelled by a magnet, or taking 
the leaf of a tree and hanging it up between the poles, to ob- 
serve it take an equatorial position. Whether any similar effects 
occur in nature among the myriads of forms which, upon all 
parts of its surface, are surrounded by air, and are subject to the 
action of lines of magnetic force, is a question which can tis 
be answered by future observation. 
2452. Of the interior of the earth we know nothing, but pie 
are many reasons for believing that it is of a high temperature. 
On this supposition I have recently remarked, that at a certain 
2 from the surfa eee substances must 
