by the sandy isthmus of Guanarteme. The sands of this narrow causeway oy planted with tamarisks, consist chiefly of the remains of shells and foraminateræ gradually consolidated into a granular limestone with marine concretions added on both sides. These recent limestones, flecked in black by voleanic sands, are employed for making excellent filtering stones, used in all the houses of Canaria. At the time of the conquest the isthmus of Guanarteme was still nearly flush with the water, and completely inundated by high tides. Some columnar and other basalts to the north-west of Isleta recall the Giant's Causeway on the north coast of Ireland.
Las Palmas, capital of the island and largest city in the archipelago, lies near this sandy limestone isthmus, at the opening of the deep Guiniguada gorge, and
on the surrounding terraces of conglomerate, where a few shady palm-groves justify its name. The upper town is occupied by the officials, the lower by the trading class, commanded on the west by the Castillo del Rey, the chief stronghold in the island. Las Palmas presents somewhat the appearance of an Arab town, with its low flat-roofed white houses looking like an irregular flight of steps. The numerous caverns in the neighbouring rocks are still inhabited, as in the time of the Berbers. Good water is brought by an aqueduct from the hills, and carriage roads lead to the surrounding outskirts. The port lies nearly two miles to the north, where the coastline curves round the isthmus of Guanarteme to Isleta. La Luz, as it is called, doubtless from its lighthouse, was greatly exposed to the east winds until the construction of the breakwater, which runs from Isleta in nine
