Fair and peaceful to all seeming were the prospects of humanity and the world when the doors of the Hyde Park Exhibition were closed for the last time, and while its materials were being removed to be erected in more than their pristine beauty on the summit of one of the finest heights which environ the sloping basin on which the British metropolis is built. But a cloud, it might be no bigger than a man's hand, but pregnant with ill, was on the horizon. The Exhibition closed a long era of peace in Europe and the world, an era which had been marred, so far as we were concerned, only by wars in our most distant Oriental dependencies; and, so far as the Continent was concerned, only by the aggressions of the potentates who constituted the Holy Alliance, by the revolutionary movements of 1848, and their sanguinary repression in the year following. Against the hopes of all, and the belief of most, good men and women, the Exhibition inaugurated one of the most martial terms of time which have formed a part of purely modern history. A year had hardly gone by ere Napoleon effected his _coup d'etat_, that fertile source of future evils--evils which are by no means yet exhausted. Then came the Russian War, which cost us in England a hundred thousand lives and at least a hundred millions of pounds. We had hardly celebrated, and rejoiced over, and illuminated our dwellings and public buildings in celebration of, the Peace of Paris, ere in India we had to put forth the utmost might of our imperial power to vindicate our "Raj" over Moslem and Hindoo, and to avenge the foul deeds done at Cawnpore. When Prince Albert was, in the mystery of providential rule, stricken down in his prime, Italy and Austria were just beginning to recover from the effects of the contests waged between trained troops at the Voltorno and by the Garibaldian guerillas in the Valteline. The first message which was conveyed by the new-laid Atlantic cable was a message of good-will from the grand-daughter of George III. to him who sat in the seat of the rebel Washington. The first experimental cable had hardly been destroyed by the potency of old ocean, churlish and jealous of the invasion of his domain, ere that great contest broke out across the Atlantic, which brought about the abolition of slavery throughout the United States. Hardly had our young Prince brought home his bonny bride ere the subjects who owed her father allegiance were called upon to hold their own against the mighty force wielded by a power, of which the queenly diadem must ere long be worn by England's dear and best-beloved daughter. The Danish War was hardly concluded ere the aggressor, returning victorious from his northern confines, turned his face to the south, and inflicted a catastrophe quite as telling and decisive upon that ancient dynasty, which has been more frequently allied with England in the great martial embroglios of the past than any other power of Europe. [Sidenote: AN ERA OF WAR.]