The climate of the different parts of the world has often been guessed at, even by men of some scientific knowledge, according to the latitude in which the country in question was situated, until Humboldt showed how independently of latitude the isothermal lines run over the globe. And even a knowledge of this is not sufficient to form a correct and reliable idea of the climate of a given locality, especially not with respect to the life of plants growing or possible of being grown there. The elevation above the sea, the exposition, the hygrometrical condition of the atmosphere, the origin and prevalence of winds at various seasons, have all something to do with the make-up of the sum total of meteorological conditions constituting the climate. The most remarkable and extreme differences in this respect are observed not only between places in Europe and America, but even on one and the same continent. The climate of Norway, for instance, is mild, though there are large tracts covered with eternal snow and ice. "When in the interior near Dovre,in the neighborhood of Schneehutten, there is a temperature of about 47° below zero; there is at the sea coast near Hardanger, 60° 1ST. L., hardly 32°, and this is perhaps the most northern point on which the grape ripens in the open air, and consequently many other less tender fruits, which far surpass in flavor those of the same kind grown in warmer or more southern countries.

At Sae-tensdale, under the 59th degree North Latitude, one thousand feet above the sea, the temperature rises in Summer, to 102° F. in the shade, and during the Winter of '73-'74, there was very little snow, in some places none. Here the Summers are shorter than in more southern latitudes, but the days are longer, and the sun setting on the 21st of June, at 9.23 P. M., and rising at 2.40 A. M.; but without the Gulf stream washing the shores, the sun would not have that effect of bringing fruits and plants to perfection in a latitude where, in America, all vegetation is at an end. Near Christiana, every peasant or farmer has his orchard. Even at Drondhjem, five degrees and a-half still further north, Juglans regia ripens its fruits; besides pears, cherries, and of course apples, etc., etc. Here they grow wheat, whilst in the same latitude in America, near the Hudson Bay, no human habitation is possible, and in Siberia the ground thaws only to the depth of two feet. Trees in full bloom at Rome, Italy, in January, do not open their buds at Boston till May, and those at Upsala, in Sweden, bloom together with those at New York, the latitude of Naples. In Scotland, where no fruit tree thrives, the Winters are milder, than those in Hungary, and still greater is the difference between the latter country, where melons, grapes, and tobacco, come to high perfection, and the Faroe Islands where neither a beech nor an oak will grow.

At Ranenfiord, Norway, they raise rye, whilst under the same latitude in America, ice and snow prevail nearly all through the Summer. Texas is situated in the same latitude as northern Africa, where the inhabitants almost subsist, with their horses and camels, on bananas and dates, eaten in the shades of Palms; none of such trees will grow in Texas, nor will the Blue Gum, Eucalyptus globulus. At San Francisco, exactly in the same latitude with Baltimore, no peach, no grape, nor even a strawberry will ripen. The only trees there possible in gardens and parks would not survive a single season in or around Baltimore, and whilst in the Eastern States, Abies excelsa is planted as a protection against the cold winds, it will not grow near San Francisco, except being protected and sheltered against the wind. In Baltimore, deciduous trees form the main stock of the plantation in parks and gardens, and evergreens are the exception; in San Francisco evergreens are the only trees possible, to the total exclusion of deciduous ones.

In Mexico, all fruits and plants known, will grow on the same line of latitude, but on different elevations over the sea.