V — THE INFLUENCE OF THE HIGH PRESSURES.
It would be highly interesting and profitable for the study of the storms, to ascertain why that particular typhoon was forced to travel along so complicated a path, We may be sure that the influence to which it had to obey was not a single and simple one, but the complex combination of many causes acting together; and the knowledge we have here of the atmospheric conditions in the Far-East is quite inadequate to solve the problem. [t may be taken for granted, that the arrangement of the high pressures on the limits of the area of the cyclone had considerable weight in the question; but with the data to hand, it is almost impossible to determine with some precision the exact positions of these atmospheric centres of action, chiefly on the side of the Pacific Ocean, where everything becomes a mere conjecture, (for the present at least), at a short distance to the East of the Loochoos and Japan.
For want of better information, and to make some inquiry in that way, we have determined and marked on the weathermaps for each day, the point where the isobaric curves of pressures, relatively high for the season (760mm or 758mm) were the most advanced in the direction of the centre of the typhoon, and the nearest to it. We have there the point in which the atmospheric slope was steeper toward the place where the air was drawn in by the girations of the vortex. These points will be found in the annexed map surrounded by circles with the dates from the 7th to the 23rd. We acknowledge the imperfections of the method, but we are only trying to do our best with the data at hand.
It will be seen that from the 7th to the 10th inclusive, the atmospheric gradient, advancing on the Pacific, then across Japan, in the NE quadrant of the cyclone, was apparently following or pressing on it and helping so to say its displacement towards the West. On the 10th, a sudden change takes place: while the slope on the NE side wanes and becomes levelled, a maximum, having certainly its central part in Mongolia appears and projects a spur on the NW side, to prevent as it were the still distant typhoon from continuing in that direction: it was just on the same date that the centre inclined gradually towards WSW then SW. From the 11th to the 13th the head of the slope remains in the NW quadrant, but retires further on the continent; at the same time the vortex moves up towards the NE; but when the high gradient returns to Chihli on the 14th, to Liaotung on the 15th and to the E coast of Korea on the 16th, we see the minimum incline to the E and the SE along an almost parallel path, When on the 17th the high point appears on the Pacific (764mm at Nemuro), the typhoon, as if feeling the new situation resumes its course towards the NNW, and henceforth it is remarkable that the typhonic centre seems to run away from the
