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ale and shorn, as in England, seldom showing a fiery face before 10 A.M. or after 5 P.M. The sea at night appeared slightly milky, like the white waters so often seen off the western coast of India. Every traveller describes the Harmatan, and most travellers transcribe the errors touching the infusoria and their coats which Ehrenberg found at sea in the impalpable powder near the Cape Verde islands. The dry cold blast is purely local, not cosmical. There is a fine reddish-yellow sand in the lower air-strata; we see it, we feel it, and we know that it comes from the desert-tracts of northern Africa. The air rises en masse from the Great Sahara; the vacuum is speedily filled by the heavier and cooler indraught from the north or south, and the higher strata form the upper current flowing from the Equator to the Poles. But 'siliceous dust' will not wholly account for the veiling of the sun and the opaqueness of the higher atmosphere. This arises simply from the want of humidity; the air is denser, and there is no vapour to refract and reflect the light-rays. Hence the haze which even in England appears to overhang the landscape when there is unusually droughty weather; and hence, conversely, as all know, the view is clearest before and after heavy showers, when the atmosphere is saturated or supersaturated.
On my return in early April we caught the northeast Trades shortly after turning Cape Palmas, and kept them till close upon Grand Canary. They were a complete contrast with the Harmatan, the firmament looking exceptionally high, and the sun shining hot, while a crisp, steady gale made the 'herds of Proteus' gambol and disport themselves over the long ridges thrown up by the cool plain of bright cerulean. The horizon, when clear, had a pinkish hue, and near coast and islands puffy folds of dazzling white, nearly 5,000 feet high, were based upon dark-grey streaks of cloudland simulating continents and archipelagoes. Within the tropics the heavens appear lower, and we never sight blue or purple water