The Miscellaneous Writings and Speeches-2 [132]
case of Birmingham, and to all the other cases which Mr Sadler mentions. Towns of 5000 inhabitants may be, and often are, as thickly peopled "on a given space," as Birmingham. They are, in other words, as thickly peopled as a portion of Birmingham, equal to them in area. If so, on Mr Sadler's principle, they ought to be as low in the scale of fecundity as Birmingham. But they are not so. On the contrary, they stand higher than the average obtained by taking the fecundity of Birmingham in combination with the fecundity of the rural districts of Warwickshire. The plain fact is, that Mr Sadler has confounded the population of a city with its population "on a given space,"--a mistake which, in a gentleman who assures us that mathematical science was one of his early and favourite studies, is somewhat curious. It is as absurd, on his principle, to say that the fecundity of London ought to be less than the fecundity of Edinburgh, because London has a greater population than Edinburgh, as to say that the fecundity of Russia ought to be greater than that of England, because Russia has a greater population than England. He cannot say that the spaces on which towns stand are too small to exemplify the truth of his principle. For he has himself brought forward the scale of fecundity in towns, as a proof of his principle. And, in the very passage which we quoted above, he tells us that, if we knew how to pursue truth or wished to find it, we "should have compared these small towns with country places, and the different classes of towns with each other." That is to say, we ought to compare together such unequal spaces as give results favourable to his theory, and never to compare such equal spaces as give results opposed to it. Does he mean anything by "a given space?" Or does he mean merely such a space as suits his argument? It is perfectly clear that, if he is allowed to take this course, he may prove anything. No fact can come amiss to him. Suppose, for example, that the fecundity of New York should prove to be smaller than the fecundity of Liverpool. "That," says Mr Sadler, "makes for my theory. For there are more people within two miles of the Broadway of New York, than within two miles of the Exchange of Liverpool." Suppose, on the other hand, that the fecundity of New York should be greater than the fecundity of Liverpool. "This," says Mr Sadler again, "is an unanswerable proof of my theory. For there are many more people within forty miles of Liverpool than within forty miles of New York." In order to obtain his numbers, he takes spaces in any combinations which may suit him. In order to obtain his averages, he takes numbers in any combinations which may suit him. And then he tells us that, because his tables, at the first glance, look well for his theory, his theory is irrefragably proved. We will add a few words respecting the argument which we drew from the peerage. Mr Sadler asserted that the peers were a class condemned by nature to sterility. We denied this, and showed from the last edition of Debrett, that the peers of the United Kingdom have considerably more than the average number of children to a marriage. Mr Sadler's answer has amused us much. He denies the accuracy of our counting, and, by reckoning all the Scotch and Irish peers as peers of the United Kingdom, certainly makes very different numbers from those which we gave. A member of the Parliament of the United Kingdom might have been expected, we think, to know better what a peer of the United Kingdom is. By taking the Scotch and Irish peers, Mr Sadler has altered the average. But it is considerably higher than the average fecundity of England, and still, therefore, constitutes an unanswerable argument against his theory. The shifts to which, in this difficulty, he has recourse, are exceedingly diverting. "The average fecundity of the marriages of peers," said we, "is higher by one-fifth than the average fecundity of marriages throughout the kingdom." "Where, or by whom did the Reviewer find it supposed," answers Mr Sadler, "that