FUNCTION OF CRITICISM IN ADVANCEMENT OF SCIENCE. 347 
the earth’s magnetic field, that the work which it would be 
required to do to accomplish such an effect at the earth 
would be entirely impossible. This argument, if true, would 
cut us off from the only solution of this great problem which 
appears to be in the least hopeful; for it is shown to be a 
fact beyond controversy that the envelopes of the sun and 
the earth are continually passing through a series of com¬ 
plicated synchronous variations. Now, something must con¬ 
nect them. What is it ? If the proposition is true that the 
sun’s work must be excessive, and that therefore there is no 
connecting bond, then the problem is well-nigh hopeless. 
But we cannot yield to this view without further examina¬ 
tion. The result of analysis is that there are three funda¬ 
mental cases for consideration: 
1. The electrostatic case, magnetic energy vanishing. 
2. The magnetic case, electrostatic energy vanishing. 
3. -Joule’s heat, electrostatic and magnetic energy. 
It takes more work to adjust the variations of the energy 
due to electric currents when propagated through an elec¬ 
trostatic field than when transmitted in a magnetic field; 
hence if the sun has a variable magnetization, due to mag¬ 
netic masses or electric-current systems passing from one 
state of equilibrium to another, the static electric field would 
require much more work than the polar magnetic field for 
these operations. To charge the electrostatic field from the 
sun to the earth is a tremendous undertaking, but the mag¬ 
netic field, on the other hand, so reacts upon the source sus¬ 
taining it as to require a minimum of work. The criticism 
is that the sun presents an instance of the second case and 
not of the first, as has been implied in the mode of thought 
heretofore presented. 
These examples must serve to explain the first canon of 
criticism on the truth or falseness of the subject-matter. 
They have been introduced on the negative side rather than 
on the positive to explain some of the principal causes of the 
failure of critical studies. There are innumerable cases 
which might have been adduced to show how false facts, 
