The difference between continental and ma rine climates is marked. The same amount of heat will raise the temperature of a land sur face four times as high as it will raise that of a water surface. Land is a good absorber and a good radiator, but it is a poor conductor and a poor reflector. The absorbed heat does not penetrate into the ground to any great depth. The land, therefore, retains its absorbed heat near the surface and quickly and freely ra diates that which it has absorbed. These con ditions give to large land surfaces much higher temperature during the day and much lower temperature during the night, than obtain over a water surface of the same latitude and much colder winters and much warmer summers. As an illustration, it may be stated that the Ber muda Islands, in the North Atlantic Ocean, have a mean daily range of temperature of only 10° F., and an annual range of only about 50° ; while Memphis, Tenn., near the same latitude, in the interior of a large continent, has a daily range of 17° and an annual range of 112°. At Memphis a temperature of 104 has been re corded in summer and — 8° in winter. At Ber muda the temperature generally reaches 90° during the summer, but very rarely exceeds that figure, while temperatures below 45° are also infrequent. The two places are typical of continental and of marine climates. All regions bordering closely on the sea partake of both climates, the predominating one being determined by the direction in which the coasts trend, their elevation and the direction and force of the prevailing winds.
In the middle latitudes of both hemispheres the prevailing winds are from the west, and therefore continents lying in these regions have a marine climate in their western coastal re gions, where the air moves from the water to the land, and nearly continental climate in their eastern coastal regions, where the general movement of the air is from the land to the sea.
The distance to which moist and equable air conditions extend inland is determined by the elevation of the land and its trend relative to the incident winds, and the proximity of moun tain ranges. The humid air from the Pacific meets the lofty range that skirts the western shore line of both North and South America; it is forced up the mountain side until the cold of elevation and the cooling of the air by expansion as it ascends cause it to precipitate its moisture mostly upon the western side of the mountain, and it passes to the interior of the continent bereft of that life-giving moisture which, were it not for the intervention of the mountains, would spread a mantle of luxuriant vegetation 1,000 miles inland. If the disinte grating effects of temperature and rainfall had worn down the Sierras, the Plateau, and the rugged crags of the Rocky Mountains to the height of the Appalachians, the vaporous at mosphere of the Pacific would flow eastward far more freely than now, and meet that which, by the convectional action of cyclones, is fre quently carried from the Atlantic Ocean and the Gulf of Mexico inland to the Mississippi Valley; then rain would be more abundant and the whole of the United States would have arable land.
The specific heat of water is greater than that of almost any other substance. It re quires 10 times the quantity of heat to raise a of water one degree that it does to raise a pound of iron one degree. Solar rays penetrate the sea to a considerable depth; they are quite uniformly absorbed by the stratum penetrated. In consequence of these laws and conditions a vast quantity of heat is stored by the ocean in the tropics and slowly given to the air as the ocean currents carry the warm water toward the poles. In this connection the writer would correct what he believes to be an exaggerated popular idea relative to the effect of the Gulf Stream on the climate of Europe. The North Atlantic circulation, flowing north ward on the western side of the ocean (except a southward current from Davis Strait that chills Labrador and somewhat affects the tem perature of the New England coast), and south ward along the coast of Europe, is many times more effective in modifying climate than is the Gulf Stream. That the western part of Europe is wanner, more -humid and subject to less radical changes in temperature than equal lati tudes in North America, except on the Pacific Coast, is due primarily to the great ocean that lies on the west of Europe. Without ocean currents of any description, this body of water would give to the air that moves from it to Europe a more equable temperature than is possessed by the eastern part of the North American continent. Continents, there f ore, partalce largely of marine climates on. their western borders, and principally of continental climates on their eastern borders.
Climate affects the health, happiness and well-being of people more than any other con dition that goes to make up their environment. Within the broad confines of the United States there are many, but not all, shades and varie ties of climate, One of the questions most f re quently asked is, (Where shall I find a climate possessing both dryness and equability of tem perature?( To this interrogatory reply must be made that the ideal climate as regards equability of temperature and absence of moist ure does not exist in the United States, but that the nearest approach to it will be found in the great Southwest.
The temperature of the Southwest is not equable in the sense of having an extremely small daily range, but it possesses the quality of annual uniformity in a greater degree than will generally be found elsewhere except on the seacoast, and there the humidity is great.