The openly declared project of the Allied Sovereigns to employ all their means, and combine all their efforts, towards the accomplishment of the complete overthrow of the resuscitated power of NAPOLEON, with whom they had determined, thenceforth, to enter into neither truce nor treaty, was singularly favoured by the circumstance of their Armies being still retained upon a war establishment. The forces of the several Powers were continued on that scale, in consequence of the difficulties experienced in the Congress in dealing with and settling many perplexing questions of international policy, and moderating the warmth of the discussions that took place upon them. It was considered expedient to keep up powerful reserves, available both for home service, and for any contingencies that might arise out of combinations and revolts among those minor States, whose aversion to the new political arrangements was more than suspected. Thus it had been found necessary to detach bodies of troops from the main bulk of the forces, in consequence of the state of the Poles placed under the protection of Russia, and of the Saxons inhabiting that portion of their country which had been ceded to Prussia; as also, in consequence of the powerful diversion, as regarded Austria, caused by the sudden irruption of MURAT, King of Naples, into the north of Italy. Notwithstanding these necessary deductions, however, it was found practicable to assemble, by the end of May, an efficient force of not less than 500,000 men, upon different points contiguous to the French frontier, with all the supplies necessary for the prosecution of a vigorous Campaign. * * * * *