Our theory has thus extended itself beyond those limits which we at first had drawn, and our apology must consist in the necessity existing for reconciling the most remarkable phenomena of meteorology to its principles. Yet, after all, what has been said is but an outline of what remains, but this outline is a part of our theory of the weather, and it could not well do without its aid. In some points we may not have correctly interpreted facts; but the facts remain. The numerical elements of the theory may also be in error--we know not; but we think that they are as perfect as the many contingencies on which they depend will permit. What is _certain_ however, is of ample value to compensate for trivial errors. We have hitherto experienced but little courtesy from those intrusted with the keys of knowledge, and cannot consequently anticipate a very lenient verdict. But we now tell them before the world, that they have a duty to perform, and an examination to make, and a decision to come to, "whether these things are so." Our theory may be called an ingenious speculation, but WE CHALLENGE THE SCIENTIFIC TO PROVE IT--NOTHING ELSE. The theory furnishes them with tests of daily occurrence, to prove or to disprove it. By such a trial we are willing to be judged; but let it be conducted in the spirit recommended in the opening address before the American Association for the Advancement of Science, to expose all false developments, and to do it generously and without prejudice; and to remember, "that the temple of science belongs to no country or clime. It is the world's temple, and all men are free of its communion. Let its beauty not be marred by writing names upon its walls."[50] The _great_ objection, of friction and resistance of an all-pervading medium, which will be urged against it, we regard as rather the offspring of a bewildered imagination, than of scientific induction. We can discover no such consequences as final ruin to our system through its agency; but even if such were discovered, we may answer, that nature nowhere tells us that her arrangements are eternal; but rather, that decay is stamped with the seal of the Almighty on every created thing. Change may be one of the great laws of matter and motion, and yet matter and motion be indestructible. The earth was called into existence for a specific object, and when that object is accomplished, we are assured that another change awaits her. But when earth, and sun, and planets, are again redissolved into their primitive state, their atoms will still float on the ever-rolling billows of the great ethereal ocean, to be again cast up, on the shore of time, whenever it pleaseth Him to say, "Let there be light." FOOTNOTES: [50] Prof. Pierce's Address, 1853. APPENDIX.