One of the most important events of this period must now be described. The hopes of the Spaniards had been raised in consequence of their recapture of the island of Minorca; General Murray, in command of Fort Saint Philip--the greater portion of his troops having died or been struck down with scurvy--after a heroic defence, having been compelled to yield. The Spanish army, which had so long been besieging Gibraltar, was now increased to 40,000 men, including 12,000 French, and, in addition, there were 47 sail of the line, 40 gunboats with heavy cannon, 40 bomb-vessels, each armed with 12-inch mortars, 5 large bomb-ketches, and 300 large boats to be employed in landing the troops as soon as a breach should be made--besides which, there were 10 large floating batteries, the invention of the Chevalier D'Arzon, a French engineer of great repute, on such a principle that they would not, he believed, be sunk or set on fire by shot. It was said that no less than 1200 pieces of heavy ordnance had been accumulated before the place, with 83,000 barrels of gunpowder, and shot, shells, military stores, and provisions in the same proportion. The chief reliance of the besiegers was, however, placed on the floating batteries. They were built of extraordinary thickness, and so fortified that they were proof from all external, as well as internal, violence. To prevent their being set on fire, a strong case was formed of timber and cork, a long time soaked in water, and enclosing a large body of wet sand; the whole being of such thickness and density that no cannon-ball could penetrate within two feet of the inner partition.