shrubs have a stunted appearance, and we need overcoats and mittens to protect us from the increasing cold. Still higher up is a vast plain, like a sea of sand, above which perpetual solitude reigns, with neither habitation nor vegetation." 12. But our course is still onward, beyond Teneriffe, and we are soon adrift again on the broad Atlantic. We are nearing the equatorial regions. We cross the tropic of Cancer, and are off the coast of the desert of Sahara,—a region of terror to me in my boyhood, inspired by the reading of Robbins and Riley's narratives of shipwreck and captivity among the Arabs. "From the green verge where Mauritania" ends, III.-Climate and Trade- Winds. Camoens. 1. During the voyage from Teneriffe, after we had passed the tropic of Cancer, we experienced very variable weather, although not so variable, Dr. Edson said, as it probably would have been if we had made the voyage in the winter season. He says this is the northern region of tropical calms, that alternate with tropical storms, and that there is a region corresponding to it, that we are to pass through, on the other side of the equator. 2. It was on a sunshiny, balmy morning, and several of our party were standing on deck, and speaking of the delightful weather, the ocean so calm, and the heavens so bright above us,-when the captain, shaking his head, and a Mauritania, the ancient Tingitana, so called from its principal city, Tingis, or Old Tangier, is now embraced in the government of Morocco. The term Ethiopia was vaguely applied to the whole of Africa south of Egypt and west to the Atlantic. pointing to a fleck of white far off on the western horizon, remarked, "We may expect rain before noon, and a storm at night." 3. And, sure enough, it was not long before a haze overspread the sky; a heavy mist, followed by rain, set in before noon, and at sunset it was blowing a gale. In the cabin, that evening, the conversation turned upon the subject of weather signs; many quaint sayings and proverbs about the weather were repeated by different members of our party, and thrilling stories were told about storms at sea. During a pause in the conversation Prof. Howard read to us the following, which he had just written out in pencil; but whether it was wholly original, or not, he did not say. It was truthful, to say the least. The Warning. 4. The morn was as bright as a morn could be; In the joy and glory of summer weather; By the next morning the storm had passed by, but there was still a heavy roll of the sea. 5. It was at this point in our voyage that the Doctor commenced a course of brief daily lectures on the science of Climatology, which were very interesting, especially to Henry and the other college graduates, who could understand and appreciate the lectures better than I could. 6. I was surprised to find that it is so much cooler in summer, and warmer in winter, on the ocean, than it is far inland; and, hence, that islands out in the ocean have a much more equable climate than inland countries. The Doctor says that on the open sea the temperature of the air never exceeds eighty-six degrees; while in sheltered places on the land, at a distance of two or three yards above the soil, in hot climates, it has occasionally reached one hundred and thirty degrees. Perhaps Mr. Agnew will explain to his pupils the causes of this difference in temperature. I am certain that they already know the uses of the thermometer. 7. After we had passed beyond the northern region of tropical calms and storms, we became aware that, from day to day, there was a steady breeze from the northward—or rather from the north-east. This wind, Dr. Edson says, is called the Trade- Wind, from its important influence in navigation; and he told us that it blows almost constantly in that one direction, in our Northern hemisphere. 8. Then he described the trade-winds, and explained their causes. He told us that, as the air is always excessively heated at or near the equator, it there rises up several miles, divides into two immense columns, and that one column then flows off toward the north pole, and the other toward the south pole, while the air on the surface of the earth or ocean rushes in-some from the north and some from the south—to fill the places which the overheated air has thus made vacant. This causes the wind to blow southward in our Northern hemisphere, just as we experienced it. Thus there is a constant circuit of the wind, back and forth, north of the equator, and a similar circuit south of it. 9. We recollected that, when we were climbing the peak of Teneriffe, and the wind was blowing southward down on the plain, the clouds were moving northward up near the summit of the mountain, and that there was a calm where we were, between the two currents. Now we had no difficulty in understanding why the clouds, up at that great elevation, were moving in a northerly direction. They had been caught by the upper current from the equator, called the anti trade-wind. 10. There were many other interesting points about these trade-winds that the Doctor explained to us. He says that, because the earth is constantly turning on its axis, from west to east, this motion of the earth causes the northern trade-wind to blow from the north-east, and the southern trade-wind to blow from the south-east; and that where these two wind-currents meet, in the equatorial regions, both take a westerly direction. 11. It was this equatorial trade-wind in the Atlantic, constantly blowing westward, that, fortunately, caught the ships of Columbus on his great voyage of discovery, and wafted them away so rapidly toward the New World. It was equally fortunate for him that he took a more northerly course on his return,-beyond the influence of the trade-winds; for, otherwise, he would probably never have returned to Spain to make known the results of his voyage. IV.-Monrovia.-Equatorial Calms. 1. Passing out of the region of tropical calms and storms, and with the trade-wind in our favor, we direct our course to Monrovia, the capital of the republic of Liberia. The territory included in this little republic, we are informed, contains a population of about seven hundred and twenty thousand, of whom twenty thousand are colored emigrants from the United States. The latter are the ruling class. 2. The town of Monrovia is only a little more than six degrees (over four hundred miles) north of the equator, yet its climate is not so hot as most of us expected to find it. We arrived there on the 1st of August. In the latitude of Monrovia, the rainy season continues from June until October; June is the coolest month of the year, and January the hottest. 3. Dr. Edson tells us that at Monrovia the mercury seldom rises above ninety degrees in the shade, and never falls below sixty. But the climate on the coast is not favorable to white men, and we soon take our departure, directing our course-sixteen hundred miles away--to St. Helena, that lone rocky isle in the South Atlantic, which derives its only historical importance from the fact that it was the great Napoleon's place of exile from October, 1815, until his death in May, 1821. 4. We had scarcely passed out of sight of land from Monrovia, when we had an opportunity to study the character of the equatorial calms that distinguish the region for several hundred miles both north and south of the equator. Often, during the day, a great calm and a great heat would prevail; the streamer at the mast-head would fall, drooping, bereft of motion; and if we had not been on board a steamvessel we should have been repeatedly becalmed in mid ocean. 5. Prof. Howard says it must have been one of these equatorial calms,-during which the sun beats down with most intense violence-that Coleridge describes in his "Rime of the Ancient Mariner:" "All in a hot and copper sky, The bloody sun at noon Right up above the mast did stand, No bigger than the moon. "Day after day, day after day, We stuck,-nor breath, nor motion ;- Upon a painted ocean." 6. But these calms are often followed by tempests that burst with a sudden fury of wind, and thunder, and lightning, unknown in other regions. We experienced one of these tempests. It was at the close of a pleasant |