TIME began to be valuable, and leaving the hospitalities of Natchez, we descended the Mississippi, to join the remnant of our large party, and make our way homewards. The Princess, with another and an agreeable set of people, returned us safely, after an absence of a week. New Orleans has been well described as a vast cotton fair, attended by representatives from all the cotton-consuming world during winter, and abandoned to the few residents who remain in summer. As most who come here to make money leave it as soon as they have accomplished their ends, there is too little public spirit, and few improvements that demand concert of action, or which are not absolute necessities, can be carried through. Its commerce is immense. The prophecies of its declension may prove true, but none who ascend its river from the Delta, passing another and another fine ship in constant succession, or who view the shipping along its wharves receiving their vast cargoes, can believe in its sudden decline. Railroads may, and do, divert the produce from certain former tributaries, but new land is every day broken up, and bales of cotton every year come to hand from some newly cultivated district; railroads may exercise a great influence in preventing the enormous increase of the city once anticipated, but its growth is still certain.

The French part of the town presents some curious differences from our stereotyped mode of building cities; a foreign air pervades it, but it is without interest after the first survey. The dead level of the site diminishes its beauty, and all picturesqneness is destroyed. Bad smells are not as prevalent as might be expected, the water of the river being let in to wash the gutters daily; mosquitoes in April, however, prove a great annoyance to us who scarcely ever have them at home, even in the warmest season.

We found Mobile in a complete turmoil with a parade of the firemen; and after a hospitable day with the celebrated and scientific Dr. Nott, took the new steamboat St. Nicholas for Montgomery, Alabama - the head of navigation, where the travel joins the system of Georgia railroads. Our boat was furnished with a machine called a " Calliope," to make music by steam 1 It was " performed" by a negro at the principal stopping places, and became a serious nuisance with its harsh and most discordant notes. Strange to say, it was, however, a most popular piece of grinding; for, generally, we found ladies and gentlemen waiting for a tune, and the negroes assembled, with their ebony skins and white teeth fully exposed.

We had a North Carolina giant on board - a huge, ungainly fellow - who was anxious to "employ" somebody to exhibit him, but was unsuccessful in finding a Barnum.

The Alabama, though so useful a river, is a very uninteresting one; it is a river of the fourth class. Till it descends into the rich bottoms of the Gulf of Mexico, it flows through the hilly region of the State, and is navigable only at high water. The valleys are clothed with a dense and luxuriant vegetation, to which the giant creepers and the palmetto give a semitropical character. The constant appearance of the Spanish moss, with its long, gray, shaggy, withered-looking growth, gives a melancholy deadness to the scene, as yon thread your way through the stream, winding and turning sufficiently to more than double the distance you wish to conquer. The forest descends to the banks of the river, and it is no uncommon thing for the overhanging branches to brush the deck of the steamer. In one or two instances, the limbs took hold of the bell, and rang a loud peal. The boat rarely stops; when it does, it pokes its nose into a high bank; boxes, bags of corn, and a few barrels of pork, are rolled out into the sand or mud, as it happens to be dry or wet, the owner, with bis gang of negroes, taking them up the hill with difficulty, and at his leisure.

Sand banks form between the different voyages; a skeleton of a steamboat may now and then be seen left upon one of these.

The ascent of the river presents the most melancholy scene. Life, there is almost none, if we except the vegetation. Once in a day you may pass a steamboat, but as to other navigation or sailing, pleasure parties, or even a ferry-boat of any importance, all is silent; the few settlements on high bluffs present nothing attractive, and look like melancholy storehouses. The inhabitants reside back from the river, where it is more healthy; scarcely a habitation presented itself for three hundred miles. These sylvan solitudes are interspersed with swamps; these are traversed by channels cutting the inhabitants off from each other, and the whole appearance of things is that of solitude brooding over unhealthy nature; dampness pervades the lowlands, and it is curious to see the puny efforts of man trying to reclaim here and there a little cotton land - all this in a country which has been called settled for half a century.

As we ascend, our Calliope startles the woods; we approach a landing, to take in wood; scows are ready loaded, the engine stops till these are fastened on each side, and, as we proceed up stream, the fuel is hastily piled upon our lower deck, the empty scows are let go, and they return with the current to their former moorings, to load for the next customer. If the landing is at a farm-house or a store, all the big and little negroes, with a few white children, range themselves on the heights above us, and dance to our half-savage music, the notes of which are about as discordant as those of a sledge-hammer. As we stop at some of the high bluffs, there are long steps of wood descending to our level, and occasionally a sort of railway, worked by a horse on the hill, pulls up or lets down the solitary individual who descends to see if there is any pork or corn to his address. We saw no mails or newspapers go ashore; these are conveyed in stages, Ac. The railroad from Mobile to Montgomery is slowly creeping along, and, when completed, will convey passengers in one day, instead of three or four.

The skill required to navigate a river such as this, must be very great. In the dark nights it must be almost impossible; if a low stage of water is added, it seems utterly impracticable. We were assured there was plenty of water by all parties, but, before reaching Montgomery, apprehensions were entertained that we might get aground. These apprehensions were not without cause, for we touched bottom often, and long poles were in the hands of the men, to lift us over. A fair rate of speed is kept up, even in the thick darkness, and were it not for the indifference to danger manifested by the habitues and the hands of the boat, a Northern traveller would feel alarm.

As soon as dinner or tea is over, all the passengers group themselves on the sides of the boat to smoke or chat. The big and little negroes assemble to dance, or lie about and play some simple game of cards.

The scene is so monotonous, that a good sleeper has the advantage over the wakeful, who, if nothing better offers, looks on at the game of cards, played, to all appearance without money, the laws of Alabama being extremely stringent on this subject. Every player is at the mercy of any informer, and the rules of the boat, unlike those on the Mississippi, do not allow of any gambling.

Bales of hay and sacks of corn, with now and then a box of claret, or barrels of pork or salt, were delivered here and there, and once a child's bathing-tub went ashore with a gentleman, who was met by his servant, to carry his coat, and the light tub was left to be sent for.

Sometimes a reach of peculiar colored wall of mud was seen rising fifteen feet from the water, as regularly formed as if made by art, and both ends well defined, having the precise appearance of the walls of a garden; and the garden itself was well represented by shrubs and trees, intermingled with the wild azalea, in white and red festoons. The cottonwood was the prevailing tree; the dogwood in blossom; the long-leafed pine and the pecan occasionally enlivened the solitary scene. As we approached Montgomery, the buckeye became common. The weather was bleak and chilly (April 12), though all the trees were in full leaf. Montgomery is a fine Southern town, but it was too wet for much exploration, and, on the 13th, we started for Atlanta, Georgia, through glorious hedges of the Cherokee Rose, in bloom, trees in leaf, Ac. Before night there was no green thing to be seen; we were on the higher grounds, and we saw no vegetation till we reached Augusta, a short stay on a Georgia plantation being our only experience of Georgia life.

Augusta has great merits as a winter residence, but our limits are reached, and we do not deem a railroad tour to Philadelphia of sufficient interest to record. We reached home on the 19th of April, and encountered the rigors of a Northern winter for some time thereafter.