A new invasion of Cuba, somewhat more formidable, but less successful even, than the former, has absorbed public attention during the past month. Immediately after the return of Lopez from his first expedition, rumors were rife that he was making preparations for another attempt. These reports, however, attracted comparatively little attention, and no effective measures were taken to put a stop to proceedings which were so palpably in violation of our treaty engagements with Spain. The reported rising of the inhabitants of Cuba at Puerto Principe, which was noticed in our last Number, and which was grossly exaggerated in public prints throughout the country, had evidently been regarded by the Cubans in the United States as eminently favorable to the prosecution of their purposes. A party of about 480 men, led by Lopez himself, and commanded by subordinate officers, accordingly embarked on board the steamer Pampero, at New Orleans, and set out for Cuba. They intended to land in the central department of the island upon the southern coast, where the disaffection had been represented as most rife, and where they were, therefore, most sure of a favorable reception. But on touching at Key West for supplies, they were informed that a revolt had taken place in the Vuelta de Abajo, and Lopez accordingly resolved to land in that district. By some mistake, the nature of which has not been clearly explained, they missed their point of destination, and landed on the northern coast of the western department of the Island on the night of the 11th of August. The shore was deserted and they met no opposition.