these rivers purify their waters in a large lake; and in their passage through the same Jurassic range of mountains they both form cataracts and waterfalls, though separated by that time by an interval of one hundred and eighty miles. Nine-tenths of the central table-lands of Switzerland belong to the Rhine system, and only one-tenth to the Rhone. In addition to these, two great rivers on the north of the St. Gothard, the Reuss and the Aar, descend in parallel ravines through rugged mountains, feeding the Lakes of Luzern, Thun, and Brienz; while on the south its snows nourish the impetuous torrents of the Ticino, which swells out into Lake Maggiore, and loses itself in the waves of the Po. Within two degrees of latitude, Switzerland contains the climate of thirty-four degrees. The variety in the vertical configuration of the country naturally affects its climate, and nearly every valley and every mountain-side has a climate of its own. Besides “mathematical climate,” which is expressed by latitude, and depends on the elevation of the surface of the earth to the sun, modern science gives “physical climate.” It describes isothermal lines, which do not exactly coincide with the circles of latitude, but diverge to north or south, according as the temperature is modified by other factors, such as the height of the land above the sea, the modifying action of mountain chains, currents of wind and water, and the neighborhood of lakes and sea. The climate of Switzerland is specially modified by the influences which spring from the capricious consequences of the nearness of mountains, which are a bulwark against the periodical agitations of the atmosphere; they form a great barrier to the northward against the icy blasts sweeping down from the snow-fields of Russia and Siberia; and to the south, to the hot Libyan winds blowing across the Mediterranean. For regular isotherms, it would be idle to seek in such a broken region. The lakes, which are fed by the glacier waters, have a cooling effect on the temperature of the summer heat; the temperature of the water of Lake Brienz does not exceed from 48° to 53° Fahrenheit in the warmest days. It is a great benefit to the circulation of air which comes in contact with surfaces so relatively cold, nor do these bodies of air carry away with them any large amount of moisture, because the low temperature of the water does not favor any great evaporation. Within a short distance one may see at the same time all the seasons of the year, stand between spring and summer,--collecting snow with one hand and plucking flowers from the soil with the other. In Valais the fig and grape ripen at the foot of ice-clad mountains; while near their summits the lichen grows at the limit of the snow-line. There is a corresponding variety as regards the duration of the seasons. In Italian Switzerland, winter lasts only three months; at Glarus, four; in the Engadine, six; on the St. Gothard, eight; on the Great St.