I have a dear friend to-day on the Atlantic. Four days ago, in New-York Harbor, I accompanied him to the floating palace that bears him to Europe; and put a book into his hand, which may furnish him some entertainment on the voyage, and some service perhaps in the land of art and beauty for which he is bound. Next Lord's Day he hopes to spend in London; and thence, after a short pause, to proceed to Rome, where he means to remain three months or more. A summer in that city is to an American somewhat hazardous on the score of health, and the facilities for seeing and exploring are far less favorable than they are in the winter. Yet, as this is the only season he can command for the purpose, he is willing to encounter the dangers and dispense with some of the advantages, for the sake of a brief sojourn in the grand old metropolis that dominated the world in the days of the Cæsars, and has since ruled it with a rod of iron in the hands of the popes. In "the historic city" he will meet with much to entertain a mind like his--highly cultivated and richly stored with classic lore; and for all that he wishes to accomplish, he will find his opportunity far too brief. But he will not be at home there--a transient and unsettled visitor. Every thing will be different from what he has been accustomed to in his own country--government different--society different--manners and customs different--churches and worship different--dress, diet and language different--architecture, public institutions, general aspect of the city, and natural scenery on all sides, quite different from any thing he ever saw before. And while he daily encounters new objects of absorbing interest--new wonders of art--new treasures of antiquity--new illustrations and confirmations of history, and feels the charm of a thousand beauties to which he has not been accustomed, the very contrast will make him confess that he is a stranger and sojourner, and think frequently of his home beyond the sunset, and sigh for the fellowship of the dear hearts far over the western sea. And should he go farther, and visit the ruined lands of the Nile--the Jordan--the Euphrates, and wander over the silent wastes that once smiled with golden harvests, glowed with gorgeous cities, and teemed with tumultuous populations; everywhere--on the burning sands of the desert--in the savage solitudes of the mountains--amidst the crumbling memorials of ancient civilizations and religions--in the tent of the Arab, the wayside encampment, and the comfortless caravansera--he will constantly require the pledge of chieftains, the protection of princes, the safe conduct of governments, and the covenanted friendship of the rude nomadic tribes among whom he makes his temporary abode.