"That," said he, "is a libel--such science will. Every one is interested in the weather--all talk about it--and thousands would carefully observe it, if they could be correctly guided in their observations." "I may get into unpleasant controversy." "Suppose you do; you can yield your position if wrong, and maintain it if right, and _magna est veritas_." "But I may be mistaken in some of the views to which it will be necessary to advert, if I attempt to systematize the subject." "Be it so--your mistakes may lead others to the discovery of the truth. Besides, the weather is _common property_, and every one has a right to theorize about it, or to talk about it, as they please--even to call a stormy day a pleasant one, or make any other mistaken remark concerning it; and every other person is entitled to a like latitude of reply. And further," said he, with some emphasis, "no important observation, in relation to a subject of such interest, should be lost; and, if you have observed one new fact, or drawn one new and just inference from those which have been observed by others; and especially if, from observation and reading, you can deduce from the phenomena an intelligible, _observable, general system_, it is not only your right, but duty, to make it known. Such a knowledge of the true system is greatly desired by every considerate man." To my friend's last argument I was compelled to yield. I could make no reply consistent with the great principles of fraternity, which I shall ever recognize. The promise was given. My friend went on his way, and I went to the daguerreotypist to procure a copy of the then appearance of the sky, as the first step toward its fulfillment. The fulfillment of that promise, reader, you will find in the following work. It was commenced as an article for a magazine, but it has grown on my hands to a volume. Justice could not well be done to the subject in less space. It has been written during occasional and distant intervals of relaxation from professional avocations, or during convalescence from sickness, and it is, for these reasons, somewhat imperfect in style and arrangement. But I have no time to rewrite. There is much in it which will be old to those who read journals of science, but new to those who do not. There is more which will be new to all classes of readers, and may, perhaps, be deemed heretical and revolutionary by conservative meteorologists; yet I feel assured that the work is a step in the right direction--that it contains a substantially accurate exposition of the Philosophy of the Weather, and valuable suggestions for the practical observer.