cool water is returning all the time and flowing in at the bottom of the caldron, while hot water is continually flowing out at the top. The ventilation of the Observatory is so arranged that the circulation of the atmosphere through it is led from this basement-room, where the pipes are, to all other parts of the building; and in the process of this circulation, the warmth conveyed by the water to the basement is taken thence by the air and distributed over all the rooms. Now, to compare small things with great, we have, in the warm waters which are contained in the Gulf of Mexico, just such a heating apparatus for Great Britain, the North Atlantic, and Western Europe. The furnace is the Torrid Zone; the Mexican Gulf and Caribbean Sea are the caldrons; the Gulf Stream is the conducting pipe. From the Grand Banks of Newfoundland to the shores of Europe is the basement-the hot-air chamber-in which this pipe is flared out so as to present a large cooling surface. Here the circulation of the atmosphere is arranged by nature; it is from west to east; consequently it is such that the warmth thus conveyed into this warm-air chamber of midocean is taken up by the genial west winds, and dispensed in the most benign manner throughout Great Britain and the West of Europe. The mean temperature of the water-heated air-chamber of the Observatory is about 90°. The maximum temperature of the Gulf Stream is 86°, or about 9° above the ocean temperature due to the latitude. Increasing its latitude 10° it loses but 2° of temperature; and after having run three thousand miles towards the north, it still preserves, even in winter, the heat of summer. With this temperature it crosses the 40th degree of North latitude, and there, overflowing its liquid banks, it spreads itself out for thousands of square leagues over the cold waters around, covering the ocean with a mantle of warmth that serves so much to mitigate in Europe the rigours of winter. Moving now more slowly, but dispensing its genial influences more freely, it finally meets the British Islands. By these it is divided, one part going into the polar basin of Spitzbergen, the other entering the Bay of Biscay, but each with a warmth considerably above the ocean temperature. Such an immense volume of heated water cannot fail to carry with it beyond the seas a mild and moist atmosphere: and this it is which so much softens the climate there. We know not, except approximately in a few places, what the depth of the under-temperature of the Gulf Stream may be; but assuming the temperature and velocity at the depth of two hundred fathoms to be those of the surface, and taking the well-known difference between the capacity of air and of water for specific heat as the argument, a simple calculation will show that the quantity of heat discharged over the Atlantic from the waters of the Gulf Stream in a winter's day would be sufficient to raise the whole column of atmosphere that rests upon France and the British Islands from the freezing-point to summer heat. Every west wind that blows crosses this stream on its way to Europe, and carries with it a portion of this heat to temper there the northern winds of winter. It is the influence of this stream upon climate that makes Erin 'the Emerald Isle of the Sea,' that clothes the shores of Albion in evergreen robes, while in the same latitude, on this side, the coasts of Labrador are fast bound in fetters of ice. In a valuable paper on Currents, Mr. Redfield states that in 1831 the harbour of St. John's, Newfoundland, was closed with ice as late as the month of June; yet who ever heard of the port of Liverpool, on the other side, though 2o farther North, being closed with ice, even in the dead of winter? Scott, in one of his beautiful novels, tells us that the ponds in the Orkneys (latitude near 60°) are not frozen in winter. The people there owe their soft climate to this grand heating apparatus, and to the latent heat of the vapours from it which is liberated during the precipitation of them upon the regions round about. Driftwood from the West Indies is occasionally cast upon the islands of the North Sea and Northern Ocean by the Gulf Stream. Nor do the beneficial influences of this stream upon climate end here. The West Indian Archipelago is encompassed on one side by its chain of islands, and on the other by the Cordilleras of the Andes, contracting with the Isthmus of Darien, and stretching themselves out over the plains of Central America and Mexico. Beginning on the summit of this range, we leave the regions of perpetual snow, and descend first into the 'tierra templada,' and then into the tierra caliente,' or burning land. Descending still lower, we reach both the level and the surface of the Mexican seas, where, were it not for this beautiful and benign system of aqueous circulation, the peculiar features of the surrounding country assure us we should have the hottest if not the most pestilential climate in the world. As the waters in these two caldrons become heated, they are borne off by the Gulf Stream, and are replaced by cooler currents through the Caribbean Sea; the surface-water, as it enters here, being 3° or 4°, and that in depth even 40° cooler than when it escapes from the Gulf. Taking only this difference in surface temperature as an index of the heat accumulated there, a simple calculation will show that the quantity of heat daily carried off by the Gulf Stream from those regions, and discharged over the Atlantic, is sufficient to raise mountains of iron from zero to the melting-point, and to keep in flow from them a molten stream of metal greater in volume than the waters daily discharged from the Mississippi River. Who, therefore, can calculate the benign influence of this wonderful current upon the climate of the South? In the pursuit of this subject the mind is led from nature up to the Great Architect of nature; and what mind will not the study of this subject fill with profitable emotions! Unchanged and unchanging, alone of all created things, the ocean is the great emblem of its Everlasting Creator. He treadeth upon the waves of the sea, and is seen in the wonders of the deep.' Yea, 'He calleth for the waters of the sea, and poureth them out upon the face of the earth.' In obedience to this call, the aqueous portion of our planet preserves its beautiful system of circulation. By it heat and warmth are dispensed to the extratropical regions; clouds and rain are sent to refresh the dry land; and by it cooling streams are brought from polar seas to temper the heat of the torrid zone. At the depth of two hundred and forty fathoms the temperature of the currents setting into the Caribbean Sea has been found as low as 48°, while that of the surface was 85°. Another cast with three hundred and eighty-six fathoms gave 43° below, against 83° at the surface. The hurricanes of those regions agitate the sea to great depths; that of 1780 tore rocks up from the bottom seven fathoms deep, and cast them ashore. They therefore cannot fail to bring to the surface portions of the cooler water below. At the very bottom of the Gulf Stream, when its surface temperature was 80°, the deep-sea thermometer of the Coast Survey has recorded a temperature as low as 35° Fahrenheit. These cold waters doubtless come down from the north to replace the warm water sent through the Gulf Stream to moderate the cold of Spitzbergen; for within the Arctic Circle the temperature at corresponding depths off the shores of that island is said to be only one degree colder than in the Caribbean Sea, while on the shores of Labrador and in the polar seas the temperature of the water beneath the ice was invariably found by Lieutenant De Haven at 28°, or 4° below the melting-point of fresh-water ice. Captian Scoresby relates, that on the coast of Greenland, in latitude 72°, the temperature of the air was 42°, of the water 34°, and 29° at the depth of one hundred and eighteen fathoms. He there found a surface current setting to the south, and bearing with it this extremely cold water, with vast numbers of icebergs, whose centres perhaps were far below zero. It would be curious to ascertain the routes of these undercurrents on their way to the tropical regions, which they are intended to cool. One has been found at the equator two hundred miles broad and 23° colder than the surface-water. Unless the land or shoals intervene, it no doubt comes down in a spirai curve, approaching in its course the Great Circle route. Perhaps the best indication as to these cold currents may be derived from the fish of the sea. The whales, by avoiding its warm waters, pointed out to the fisherman the existence of the Gulf Stream. Along our own coasts, all those delicate animals and marine productions which delight in warmer waters are wanting, thus indicating, by their absence, the prevalence of the cold current from the north now known to exist there. In the genial warmth of the sea about the Bermudas on one hand, and Africa on the other, we find in great abundance those delicate shellfish and coral formations which are altogether wanting in the same latitudes along the shores of South Carolina. The same obtains in the west coast of South America; for there the immense flow of polar waters, known as Humboldt's Current, almost reaches the Line before the first sprig of coral is found to grow. A few years ago great numbers of bonita and albercore (tropical fish), following the Gulf Stream, entered the English Channel, and alarmed the fishermen of Cornwall and Devonshire by the havoc which they created among the pilchards. It may well be questioned if the Atlantic cities and towns of America do not owe their excellent fish-markets, and the watering-places their refreshing sea-bathing in summer, to this littoral stream of cold water. The temperature of the Mediterranean is 4° or 5° above the ocean temperature of the same latitude, and the fish there are, for the most part, very indifferent. On the other hand, the temperature along the American coast is several degrees below that of the ocean, and from Maine to Florida, tables are supplied with the most excellent of fish. The sheep's-head of this cold current, so much esteemed in Virginia and the Carolinas, loses its flavour, and is held in no esteem, when taken on the warm coral-banks of the Bahamas. The same is the case with other fish: when taken in the cold water of that coast they have a delicious flavour, and are highly esteemed; but when taken in the warm water on the other edge of the Gulf Stream, though but a few miles distant, their flesh is soft and unfit for the table. The temperature of the water at the Belize reaches 90°. The fish taken there are not to be compared with those of the same latitude in this cold stream. New Orleans, therefore, resorts to the cool waters on the Florida coasts for her choicest fish. The same is the case in the Pacific. A current of cold water from the south sweeps the shores of Chili, Peru, and Columbia, and reaches the Gallipagos Islands under the equator. Throughout this whole distance the world does not afford a more abundant or excellent supply of fish. Yet out in the Pacific, at the Society Islands, where coral abounds, and the water preserves a higher temperature, the fish, though they vie in gorgeousness of colouring with the birds and plants and insects of the tropics, are held in no esteem as an article of food. I have known sailors, even after long voyages, still prefer their salt-beef and pork to a mess of fish taken there. The few facts which we have bearing upon this subject seem to suggest it as a point of the enquiry to be made, whether the habitat of certain fish does not indicate the temperature of the water, and whether these cold and warm currents of the ocean do not constitute the great highways through which migratory fishes travel from one region to another? Why should not fish be as much the creatures of climate as plants, or as birds and other animals of land, sea, and air? Indeed, we know that some kinds of fish are found only in certain climates: in other words, they live where the temperature of the water ranges between certain degrees. Flooring, roofing, &c. : MENSURATION. (1) How many squares (each 100 square ft.) are there in a close fence round a garden, measuring 325 ft. 9 in. long, and 23 ft. 6 in. wide, its height being 18 ft.? (2) What would painting the above cost, at 5s. 7d. per square? (3) What will be the cost of slating the roof of a house which is 68 ft. in depth and 40 ft. in width, the rafters of which are 'true pitch (i.e. each the width of the house), at 9s. 6d. per square? Plumbers' work: (4) How much lead of 10 lbs. to the square foot will line a rectangular cistern, without a lid, 5 ft. 9 in. long, 4 ft. wide, and 3 ft. 6 in. deep (interior measurement)? (5) What will the covering and guttering a roof with lead cost at 18s. per cwt., the length of the roof being 43 ft., and breadth or girth over it 32 ft., the guttering 57 ft. long and 2 ft. wide-supposing the former to be 94 lbs. and the latter 71⁄2 lbs. to the square foot? A SKETCH OF THE RISE OF BRITISH (From the speech [fourth day] of Mr. Burke on the impeachment of Warren Hastings.) con-tin'-gent (n.), proportion, chance mu-ni'-cip-al, belonging to a corporation te-na'-cious, holding fast hired su-per-sede', to set aside, to set above |