All this is now explained by known forces in Nature. Of these the most important is a thermal current in the Pacific, corresponding to the Gulf Stream in the Atlantic. The latter, having its origin in the heated waters of the Gulf of Mexico, flows as a river through the ocean northward, encircling England, bathing Norway, and warming all within its influence. A similar stream in the Pacific, sometimes called the Japanese Current, having its origin under the equator near the Philippines and the Moluccas, amid no common heats, after washing the ancient empire of Japan, sweeps north, until, forming two branches, one moves onward to Behring Strait, and the other bends east, along the Aleutian Islands, and then south, along the coast of Sitka, Oregon, and California. Geographers have described this “heater,” which in the lower latitudes is as high as 81° of Fahrenheit, and even far to the north as high as 50°. A chart in Findlay’s “Pacific Ocean Directory” portrays its course, as it warms so many islands and such an extent of coast. An officer of the United States Navy, Lieutenant Bent, in a paper before the Geographical Society of New York, while exhibiting the influence of this current in mitigating the climate of the Northwest Coast, mentions that vessels on the Asiatic side, becoming unwieldy with accumulations of ice on the hull and rigging, run over to the higher latitude on the American side and “thaw out.” But the tepid waters which melt the ice on a vessel must change the atmosphere, wherever they flow.
I hope you will not regard the illustration as too familiar, if I remind you that in the economy of a household pipes of hot water are sometimes employed in tempering the atmosphere by heat carried from below to rooms above. In the economy of Nature these thermal currents are only pipes of hot water, modifying the climate of continents by carrying heat from the warm cisterns of the South into the most distant places of the North. So also there are sometimes pipes of hot air, having a similar purpose; and these, too, are found in this region. Every ocean wind, from every quarter, traversing the stream of heat, takes up the warmth and carries it to the coast, so that the oceanic current is reinforced by an aërial current of constant influence.
These forces are aided essentially by the configuration of the Northwest Coast, with a lofty and impenetrable barricade of mountains, by which its islands and harbors are protected from the cold of the North. Occupying the Aleutian Islands, traversing the peninsula of Alaska, and running along the margin of the ocean to the latitude of 54° 40´, this mountain-ridge is a climatic division, or, according to a German geographer, a “climatic shed,” such as perhaps exists nowhere else in the world. Here are Alps, some of them volcanic, with Mount St. Elias higher than Mont Blanc, standing guard against the Arctic Circle. So it seems even without the aid of science. Here is a dike between the icy waters of Behring Sea and the milder Southern Ocean. Here is a partition between the treeless northern coast and the wooded shores of the Kenaians and Koloschians. Here is a fence which separates the animal kingdom, having on one side the walrus and ice-fox from the Frozen Ocean, and on the other side the humming-bird from the tropics. I simply report the testimony of geography. And now you will not fail to observe how by this configuration the thermal currents of ocean and air are left to exercise their climatic power.
One other climatic incident here is now easily explained. Early navigators record the prevailing moisture. All are enveloped in fog. Behring names an island Foggy. Another gives the same designation to a cape at the southern extremity of Russian America. Cook records fog. La Pérouse speaks of rain and continued fog in the month of August. And now visitors, whether for science or business, make the same report. The forests testify also. According to physical geography, it could not be otherwise. The warm air from the ocean, encountering the snow-capped mountains, would naturally produce this result. Rain is nothing but atmosphere condensed and falling in drops to the earth. Fog is atmosphere held in solution, but so far condensed as to become visible. This condensation occurs, when the air is chilled by contact with a colder atmosphere. These very conditions occur on the Northwest Coast. The ocean air, coming in contact with the elevated range, is chilled, until its moisture is set free.
Add to these influences, especially at Sitka, the presence of mountain masses and of dense forests, all tending to make the coast warmer in winter and colder in summer than it would otherwise be.
Practical observation verifies these conclusions of science. Any isothermal map is enough for our purpose; but there are others which show the relative conditions generally of different portions of the globe. I ask attention to those of Keith Johnston, in his admirable Atlas. But I am glad to present a climatic table of the Pacific coast in comparison with the Atlantic coast, recently compiled, at my request, from the archives of the Smithsonian Institution, with permission of its learned secretary, by a collaborator of the Institution, who visited Russian America under the auspices of the Telegraph Company. By this table we are able to comprehend the relative position of this region in the physical geography of the world.
| Places of Observation. | Mean Temperature in Degrees Fahrenheit. | Precipitation in Rain or Snow. Depth in Inches. | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Spring. | Summer. | Autumn. | Winter. | Year. | Spring. | Summer. | Autumn. | Winter. | Year. | |
| St. Michael’s, Russ. Am. Lat. 63° 28´ 45´´ N. | 28.75 | 52.25 | 27.00 | 7.00 | 27.48 | … | … | … | … | … |
| Fort Yukon, Russ. Am. Lat. (near) 67°. | 14.22 | 59.67 | 17.37 | -23.80 | 16.92 | … | … | … | … | … |
| Ikogmut, Russ. Am. Lat. 61° 47´ | 19.62 | 49.32 | 36.05 | 0.95 | 24.57 | … | … | … | … | … |
| Sitka, Russ. Am. Lat. 57° 3 | 39.65 | 53.37 | 43.80 | 32.30 | 42.28 | 18.32 | 15.75 | 32.10 | 23.77 | 89.94 |
| Puget Sound, Wash. T. Lat. 47° 7´ | 48.88 | 63.44 | 51.30 | 39.38 | 50.75 | 7.52 | 3.68 | 15.13 | 20.65 | 46.98 |
| Astoria, Oregon Lat. 46° 11´ | 51.16 | 61.36 | 53.55 | 42.43 | 52.13 | 16.43 | 4.85 | 21.77 | 44.15 | 87.20 |
| San Francisco, Cal. Lat. 37° 48´ | 55.39 | 58.98 | 58.29 | 50.25 | 55.73 | 6.65 | 0.09 | 2.69 | 13.49 | 22.92 |
| Nain, Labrador Lat. 56° 10´ | 23.67 | 48.57 | 33.65 | 0.40 | 26.40 | … | … | … | … | … |
| Montreal, Canada East Lat. 45° 30´ | 41.20 | 68.53 | 44.93 | 16.40 | 42.77 | 7.66 | 11.20 | 7.42 | 0.72 | 27.00 |
| Portland, Maine Lat. 43° 39´ | 40.12 | 63.75 | 45.75 | 21.52 | 42.78 | … | … | … | … | … |
| Fort Hamilton, N. Y. Lat. 40° 37´ | 47.84 | 71.35 | 55.79 | 32.32 | 51.82 | 11.69 | 11.64 | 9.88 | 10.31 | 43.52 |
| Washington, D. C. Lat. 38° 54´ | 54.19 | 73.07 | 53.91 | 33.57 | 53.69 | 10.48 | 10.53 | 10.16 | 10.06 | 41.23 |
It is seen here that the winters of Sitka are relatively warm, not differing much from those of Washington; but the summers are colder. The mean temperature of winter is 32.30°, while that of summer is 53.37°. The Washington winter is 33.57°; the Washington summer is 73.07°. These points exhibit the peculiarities of this coast,—warm winters and cool summers.
The winter of Sitka is milder than that of many European capitals. It is much milder than that of St. Petersburg, Moscow, Stockholm, Copenhagen, Berlin, or Bern. It is milder even than that of Mannheim, Stuttgart, Vienna, Sebastopol in the Crimea, or Turin. It is not much colder than that of Padua. According to observations at Sitka in 1831, it froze only two days in December and seven days in January. In February, the longest frost lasted five days; in March, it did not freeze during the day at all, and rarely in the night. During the next winter, the thermometer did not fall below 21° Fahrenheit; in January, 1834, it reached 11°. On the other hand, a temperature of 50° has been noted in January. The roadstead is open throughout the year, and only a few landlocked bays are frozen.