No great progress is made in the sieges of Gibraltar and Mahon; on the 27th ult., the enemy made a sally from the former place, in which they did more damage, than has been published here, having completely ruined the advanced works of the besiegers, the repair of which will require some time and much money. At Mahon, the rainy season has retarded the operation of the assailants. I am just told the Duc de Crillon demands a reinforcement of two thousand men, which will be granted to him. The enemy receives small succors from time to time by sea. The Court is about to negotiate another loan, in which if it does not succeed, perhaps it must have recourse to another emission of paper. The treasury is at a low ebb. The Minister of Marine demanded lately ten millions of reals, and received but three. The credit of the paper has lately risen, it is not negotiated at one and a half per cent loss. A plan for a national bank, is at present before the Council. The projector, M. Cabarrus, proposes to form a capital of fifteen millions of dollars, of which he offers to procure six millions; each action to amount to two thousand reals, for which the proprietors receive a certain interest of four per cent, with the profits expected from this establishment; I have seen the plan, but had not permission to copy it, so that I can give but a faint sketch of it. Eight directors are to be chosen the first year, and six annually, by the assembly of the proprietors; two of these directors are to be perpetual, because it is proposed, that they should have the direction of the supplies for the army and navy, with an interest of ten per cent, to the emolument of the bank; these two directors are to be named by the Court, out of four chosen by the proprietors; in other respects the Court to have no influence. If this plan, which was originally a part of the scheme for the circulation of paper here, should succeed, the paper which will be discounted by it, will probably preserve its credit. The Gromios, companies possessed of exclusive privileges, will be annihilated, and much money, now dormant in the coffers of individuals, be called into circulation. The Gromios pay two and a half per cent interest, and the bank four, which difference, joined to the hopes of farther profits, will tempt the money-holders to withdraw their funds from the hands of the first, and place them in the latter. But these companies and their friends, oppose it strongly, as do also the persons employed in supplying the army and navy, with whom, it is said, people in various departments of Government have interested connexions.