with reference to which the solar motion would be reversed 180° from the value assigned above."1 It appears then, that whether we consider the effects of gravitation, which almost always lead to motions either in elliptical orbits or in some other allied curves; or whether we take into account the extreme uncertainty, if not total invalidity, of the data on which all determinations of the sun's motion through space depend, my chief astronomical critics have misled their readers by setting before them the supposed motion of the sun, as if it were certainly in a straight line and not in some orbit around a centre, and also as if both its direction and velocity were determined by methods of observation as secure as those by which the distances of the sun and of the nearest stars have been measured. So far then, as the objections to my views depending upon the sun's motion through space are concerned, I submit that I have shown them to be wholly worthless. (3) The third most confidently stated criticism of my article was, that even if we were in a central position in the stellar universe, and if that position were a permanent one, it would not be of the least use to us as an inhabited world. Professor H. H. Turner says: "We have no reason for supposing that if the stars were blotted out of existence our Sun would become dead and cold sensibly sooner than under present conditions. The accepted belief is, that his slow contraction is sufficient to account for the energy radiated, and other observed phenomena; and it has never, so far as I am aware, been suggested that we are kept alive by the attractive powers of our neighbours, the fixed stars, or by their influence in any other form. We might wander into outer space without losing anything more serious than we lose when the night is cloudy and we cannot see the stars." 2 Now this way of looking at the question is a very one-sided and imperfect one. We are situated in a vast universe and are products of it. We cannot detach ourselves from it and say "We do not want the rest of the universe; the stars are no good to us; so long as we have our sun all the rest may go." The universe is a mighty organism: its whole aspect and structure assure us of the fact. We are a portion of it, and owe our position, our surroundings, our very existence to it. Looking at it as an evolutionist, I believe that it is only by tracing it back to some necessary earlier state that we shall be able to form some rational conception of how it has evolved, how it has come to be what it is, how we have come to be where we are. Then, and then only, shall we (1) The Astrophysical Journal, vol. xiii., p. 87. 1901. be able to give any probable answer to the question-What advantages have we derived from our nearly central position? On all these points I could find hardly any suggestions of enlightenment in astronomical literature, but, rather, what seem to me now to be unnecessary difficulties thrown in the way of the enquirer; and at the time I wrote my article I had no clear ideas on the subject myself. Hence my vague and weak suggestion of stellar radiations affecting us. But, having undertaken to write a book upon the same subject as my article, I have, for some three or four months, been almost daily more or less occupied with it, and have quite recently reached what is, to myself at all events, a satisfactory explanation. Light first came to me through reading (so far as a nonmathematician can read such a work) Lord Kelvin's remarkable article in the Philosophical Magazine of January, 1902, "On the Clustering of Gravitational Matter in any part of the Universe." In the first place, this removed the difficulty, which almost all writers upon the Stellar Universe had dwelt upon, as to the proper motions of the stars being often so large that they could not have been produced by gravitation within the universe. By different, but yet quite probable assumptions as to the primitive extent of the universe and the mass of matter within it, Lord Kelvin shows that the average proper motions are such as could be produced by gravitation. But he does not, as I had hoped he would have done, go on to explain how his preliminary assumptions would or might lead to a universe constituted like that which we see around us. Having arrived at the last chapter of my book I was for some weeks puzzling myself over this problem, some solution of which I felt to be essential to the completion of my work; and at last— as I usually find to be the case-the sought-for solution came to me, and brought with it as I had expected it would bring, a very clear explanation of the extreme importance of our central position as the only one which could afford the conditions which are absolutely essential for the long processes of life-development. This enabled me to complete my work, which is now ready for the press, and I hope will be published shortly after the appearance of this article. The careful study of the whole subject during the preparation of this work has greatly strengthened the position I took in my first article. In the portion devoted to the biology and physics of the earth and solar system especially, I have found that such delicate adjustments and such numerous combinations of physical and chemical conditions are required for the development and maintenance of life as to render it in the highest degree improb able that they should all be again found combined in any planet; while within the solar system this improbability approaches very near indeed to a certainty. This part of my work contains so much novel and suggestive matter as to throw quite a new light on a subject which, so far as I know, has never before been so fully discussed. In the astronomical portion of the volume also, I have shown that a large body of facts, due to recent researches, have a direct bearing upon the question of there being other inhabited planets revolving around other suns. On this question of course there can be no direct evidence; but the facts that I adduce will, I think, satisfy those who come to the subject without prepossessions on one side or the other that the combination of probabilities against such an occurrence are so great as to lead to the provisional conclusion that our earth is the only inhabited planet in the whole Stellar Universe. ALFRED R. WALLACE. FREE TRADE AND ITS FRUITS. "WE boom and you crab." So said an American friend to me last year, when the great ocean combine was the subject of agitated discussion in so many newspapers. The contrast between our English habit of clamorously announcing to the world some supposed catastrophe to British trade and the American habit of proclaiming a "gigantic success" on the most trivial grounds struck him as scarcely anything else in this country. Nevertheless, until a few months ago, though we might "crab" our trade, we still retained a buoyant pride and confidence in our Empire, which we imagined to be great, glorious, and prosperous, and uniquely distinguished from all others because it was held together by the silken ties of sentiment and affection. But in a few weeks all this has changed. We now have the Colonial Secretary, whose long administration was supposed to have created a new and greater epoch of Colonial loyalty, suddenly beginning to speak as if the Empire also were on the verge of collapse and its "silken ties" a complete illusion. We have poured out blood and treasure without stint during the last four years for the security of the Colonial Empire, and this, after all, is the result, and it is Mr. Chamberlain who tells us! Eight years of his administration have brought us to a point of danger undreamt of when he took office; and the whole world. is called upon to witness, not merely how British trade is decaying, but what a brittle, unsubstantial fabric is this sanguine dream of sentimental imperial loyalty. Such also is the tale which "Calchas" has unfolded to us in the July and August numbers of this review. It reaches its climax with the suggestion in the August number that Colonial sentiment was an evanescent feeling due to the sex and age of the late Queen. Pro-Boers have had their heads or their windows broken for saying much less than this; and imagination boggles at the thought of what Mr. Chamberlain would have said at the election of 1900, if any opponent had ventured to hint even the half of it during that conflict. But, of course, if it is true, it must be told, and we must even applaud the courage which faces the disagreeable truth. Nevertheless, it is so sudden and the secret has hitherto been so well kept that we are entitled to ask for very particular proof. What is the avowed object of making the disclosure at the present time? It is that at the next election Mr. Chamberlain may be armed with the free hand against Free Trade. More or less than that it is impossible to say, for Mr. Chamberlain himself and "Calchas," his spokesman, whose articles I propose to examine, are themselves wholly vague as to the final outcome. Their argument wavers between protectionism and imperialism. At one moment we are adjured to make a sacrifice that the Empire may be saved, at the next to rise as one man against the fiscal folly which permits the foreigner to invade our home markets. "Calchas" appears to be rather doubtful whether the British public will rise to the first of these appeals, but he is quite certain that they will descend to the second. They are, he keeps insisting, protectionist at heart; they want to bite the foreigner and strike back at him when he dares send his goods into their market and makes it difficult for them to send their goods into his market. Thus Mr. Chamberlain has a double line of advance. If he cannot succeed by saying that every vote for his opponents is a vote against the Empire, he can still have an orgy of fiscal jingoism in which his splendid talent for inciting his countrymen against foreigners will have its finest opportunity. The new policy being thus quite vague, I do not propose to trouble the reader with any detailed statement of the case against preferential tariffs. But it is impossible quite to pass over either the singularly misleading figures which "Calchas" gives us in respect to the Canadian preference or his honest conviction, expressed with such fervour in the August number, that the Empire will be broken if Mr. Chamberlain fails to carry this part of his proposals. "Our trade with Canada," he tells us (July number, page 28), "formerly sinking from year to year, has recovered and doubled in value." The Canadian preference is, therefore, said to be an asset worth as much as our whole export trade to Russia." After much casting about for the clue to this statement, I conjecture that "Calchas," who on almost all other occasions takes exports as the test of foreign trade, has on this occasion taken the whole increase both in exports and imports since 1897 and (1) credited it all to the preferential system, and (2) compared it with the cxports alone of our Russian trade. Such a method of dealing with the figures is, of course, wholly unpermissible. The total increase in our exports to Canada is less than half the total of our Russian exports, but in order to ascertain the true effect of the preference we have first to eliminate the articles which have gone into Canada either free or under tariffs not affected by the preference, and next to consider the general course of trade with Canada since 1897. Now, there has been an all-round increase in Canadian trade since 1897, of |