PLATE 26. DEFLECTING FORCES, The “S-shaped” curves are divided into twelve parts to denote the path traversed by a particle of air, in each of the months of the year, when subjected to the winds that are found at Amherst, Massachusetts, Easton, Pennsylvania, New York City, Paris and Pekin, which are taken as representative places. In each case is seen the "parallelogram of forces," of which the diagonal represents the monthly resultant, one side one-twelfth of the yearly resultant, and another side the monsoon influence. Near each is gathered a parallel series of arrows to show the position of these monsoon influences relative to each other. The law of the Monsoon Influences is seen in two facts: 1st. All these places, except Paris, are situated on the western shore of the adjacent oceans, and their monsoon influences are from the southsoutheast in summer, and from the north-northwest in winter; but at Paris, not thus situated, their direction is reversed. And 2d. The monsoon influences at Pekin, which is emphatically in the monsoon region, and at New York, which is near the ocean, are greater than those at the other places which are not thus situated. In the diagram at the right, in this Plate, representing an aggregate period of 560 years of observation, taken at more than 60 places in the State of New York, the approximate parallelism and equality of the arrows show the permanent character of the winds, and their divergence or inequality their annual mutations; yet the latter are rather apparent than real, since they are due chiefly to the introduction of new stations or discontinuance of old stations, so producing a slight modification of the result, and not indicating any really marked differences in the annual resultants. Two striking instances of diurnal variation in the direction of the wind are given on the lower part of the Plate for Hudson, Ohio, and St. Petersburg, which are easily explained by the proximity of each of these places to a considerable body of water situated north and northwest of them. SOUTHERN IMITADY POLAR SYSTEM 7150 North Latitude Ulea Sold Aland Islands 80° North Latitude PLATE 2. 180 120 110 60 50 Nasimowo Zlatousto (Bache Aktolik ctia Nertchinek Nino Tagulat Kazan Bogoalomik bi Novogoro Viatks Vladimir Kostroms Moscow Totma Vologdao os RU S SI A 155 Okotek Okotsk 30 Archangel Ligatel Onega St. Petersburg JPRE SEA Dorpat Kem Riga FINLAND Laked elastfors Kajan Petronatulala 160 Palviamo Bio Remo Genset Mites Ups fiefhe Nifne Kumsk locum Hermosen Fahlan Tromsoe Stengele Ostersund NORWAY Dear and Drontheim |