A striking single fact in connection with these figures, giving them point as less extreme variations could not do, is found in the behavior of clearings when the Stock Exchange was closed, during the crisis of 1914. At that time, New York clearings, which had been about twice as great as country clearings, fell suddenly _below_ country clearings. When the Stock Exchange was opened, the old proportions suddenly reappeared. That speculation spreads far beyond New York, New York being the centre for dealings in securities, etc., which involve the whole country, is, of course, well known. The extent of this Mr. Silberling seeks to measure by correlating clearings outside New York with New York share sales. His weekly correlation for these two variables for 1909-10 gives r = .368(103), and the correlation for the mid-weeks gives a higher figure, r = .424(46). The monthly correlation shows r = .257(23), a lower figure, "which is perhaps due in part to the fact that the bulk of the outside monthly clearings show relatively moderate fluctuations, because of their diverse composition, and are less sensitive than the periods of shorter length." Seeking an index of the variations of that trade which is, in Professor Fisher's phrase, governed by "physical capacities and technique"--a law which Professor Fisher,[259] as we have seen, would apply to the great total of 387 billions which he has constructed--Mr. Silberling chooses the gross earnings of the principal railways as the best available test. Railways deal with all manner of other enterprises. He correlates this with clearings outside New York. "The question might arise at once whether changes in traffic are strictly concomitant with changes in payments involved by it, and therefore with the clearings resulting. The preliminary hypothesis that a 'lag' ensued between traffic and the bulk of the payments was first tested by correlating the railway figures with clearings of one month[260] and two months later, but no correlation was obtained. The direct month-to-month correlation yielded, however, a result r = .524(23)." This suggests that outside clearings are, in substantial degree, an index of physical trade, but Mr. Silberling calls attention to certain chance agreements between railway traffic and speculation in cotton and produce and grain, speculation in the crops which are in current movement, and regularly recurring concomitances between traffic and speculation in March, when the railway traffic revives after the February lull, and when there is a large mass of dealing in Spring deliveries in Chicago. In view of the facts later to be developed, with reference to the small actual value of the necessary physical exchanges (partially covered already) as compared with clearings, this query is well put. We may easily have here a "spurious" correlation. Taking it at its face value, however, and taking the correlation as indicating the influence of physical trade on bank