_Moscas_ of a larger variety also infest the lagoons of the old town, but mosquitoes are rare, and further inland unknown, for Leon is the gate city of the western highlands, one of its suburbs being only a short distance from the foothills of the Cerro de las Pilas, a naked peak whose summit affords a complete panorama of the lake region and the coast range. In the north the Sierra Madre of Honduras looms on the horizon like a white-crested cloud, flanked by the blue ridge of the coast range, and the volcanic domes of the central plateau which attains its maximum altitude in the uplands of Matagalpa. But forty miles southeast of Leon the great tableland which stretches in an almost unbroken line from Denver across Mexico and the highlands of Central America is intersected by the basin of the Isthmus lakes; and here, as if the disruption of the Sierra had opened a vent for the furnaces of the nether world, volcanoes and hot springs are massed in a way which to my knowledge is paralleled only in the Island of Java, where a highland region of twelve hundred square miles is veiled with the almost perpetual smoke of its burning mountains. About twenty miles north of Las Pilas the continuity of the coast range is broken, and the main chain seems to be segregated into numerous isolated mountain groups, each of them crowned with two or three volcanic cones. At the end of the cape which forms the breakwater of the sound known as the Estero Real stands the volcano of Conseguina, the Vesuvius of the New World. In one of its last eruptions it caused an inundation by completely obstructing the outlet of the Rio Casco, and in 1835 it scattered its ashes as far as La Guayra and Tehuantepec, _i. e._, over a circle fourteen hundred miles in diameter. The head of the bay is begirt by the dolerite cliffs of two other volcanoes, one of which fronts the shore with a sheer precipice of 4,400 feet, rising from a pedestal of rock colonnades with cavernous interspaces where trickling springs have generated a rank vegetation of climbing evergreens. The same arrangement repeats itself at the head of Lake Managua, where the volcano of Monotombo rises in tower-like basalt cliffs to a vertical height of 7,400 feet. Professor Vanhouten, of the canal survey, makes the highest point of the peak 7,700—at all events a thousand feet more than the summit of Mount Washington. The “South Dome” of the Yosemite, if my memory serves me right, rises hardly 5,000 feet above the valley, and the granite front of the “Captain” considerably less than 4,000, while the grandeur of the basalt coliseum is yet doubled by the mirror of the Island Sea, as the first colonists translated the Indian name of Lake Managua. The lake is dotted with wooded islands which accompany the south shore into the strait of Panalaya, and where that strait opens into the broad basin of the lower lake, the islands, too, expand, two of them so much, indeed,