114 
Remarks on Professor Hansteen’s 
The diameter of the largest of the animalcules was only the 
jij^^th of an inch, and many only the army 
which Buonaparte led into Russia in 1812, estimated at 500,000 
men, would have extended, in a double row, or two men a-breast, 
with 2 feet 3 inches space for each pair of men, a distance of 106f 
English miles ;-^the same number of these animalcules, arranged 
in a similar way in two rows, but touching one another, would 
only reach 5 feet 2 J inches ! A whale requires a sea, an ocean, 
to sport in ; about a hundred and fifty millions of these animal- 
cules would have abundant room in a tumbler of water. 
AtiT. 'KYll,-^Remarks on Professor Hansteen's Inquiries 
concerning the Magnetism of the Earth.” (Concluded from 
Vol. III. p. 138.) 
The few facts hitherto discovered respecting the nature of 
artificial magnets, afford us little assistance in eixamining the 
great terrestrial magnet: the acquaintance we have with the one, 
is much too limited for illustrating the phenomena of the other ; 
and our knowledge of each is almost wholly derived from ob- 
servations which have no direct reference to any thing beyond 
its own properties. So long, however, as this continues to be 
true, our researches concerning the magnetism of the earth can- 
not be expected to possess the precision and completeness cha- 
pcteristic of science ; and while so many other obstacles conti- 
nue to retard the progress of both, great part of the subject 
must remain enveloped in obscurity. At first view, indeed, the 
results present nothing but the most perplexing intricacy. The 
magnetic intensity varying at different times, and at different 
places in the same time ; the lines of equal dip, and the lines of 
equal variation, arranged in such complex forms, and changing 
their position with inconstant rapidity, at one time to the east, 
at another to the west, appear to indicate the agency of forces 
so numerous and so entangled, as to set our power of estimating 
them for ever at defiance. By degrees, however, some kind of 
regularity is found to exist among the various observations : the ef- 
fects of certain leading principles arise dimly above the crowd of 
