Page:Physical Geography of the Sea and its Meteorology.djvu/440

414 month and from the course upon which he is about to make an entry, he has already made four marks or scores, thus (////). The one that he has now to enter will make the fifth, and he "scores and tallies," and so on until all the abstracts relating to that part of the ocean upon which he is at work have been gone over, and his materials exhausted. These "fives and tallies" are exhibited on Plate V. Now, with this explanation, it will be seen that in the district marked A (Plate V.) there have been examined the logs of vessels that, giving the direction of the wind for every eight hours, have altogether spent days enough to enable me to record the calms and the prevailing direction of the winds for eight hours, 2144 times : of these, 285 were for the month of September; and of these 285 observations for September, the wind is reported as prevailing for as much as eight hours at a time: from N. 3 times; from N.N.E., 1; N.E., 2; E.N.E., 1; E., 0; E.S.E., 1; S.E., 4; S.S.E., 2;S., 25; .S.S.W., 45; S.W., 93; W.S.W., 24; W., 47; W.N.AV., 17; N.W., 15; N.N.W., 1; Calms (the little O's), 5; total 285 for the month in this district. The number expressed in figures denotes the whole number of observations of calms and winds together that are recorded for each month and district. In C, the wind in May sets one third of the time from west. But in A, which is between the same parallels, the favourite quarter for the same month is from S. to S.W., the wind setting one third of the time from that quarter, and only 10 out of 221 times from the west; or, on the average, it blows from the west only 1⅓ day during the month of May. In B, notice the great "sun swing " of the winds in September, indicating that the change from summer to winter, in that region, is sudden and violent; from winter to summer, gentle and gradual. In some districts of the ocean, more than a thousand observations have been discussed for a single month, whereas, with regard to others, not a single record is to be found in any of the numerous log-books at the National Observatory.

782. Typhoons.—The China seas are celebrated for their furious gales of wind, known among seamen as typhoons and white squalls. The seas are included on the plate (VIII.) as within the region of the monsoons of the Indian Ocean. But the monsoons of the China Sea are not five month monsoons (§ 681); they do not prevail from the west of south more than two or three months. Plate V. exhibits the monsoons very clearly in a