Second: A victory on the Var was of much greater importance to Melas than was the capitulation of Genoa; for should this river be once forced, there would be no further obstacle to the invasion of France; and, besides, a successful attack on Suchet would hopelessly deprive Masséna of all support, and would in time force him to surrender. In truth, the great effort for success should have been made on the Var. But Melas failed to appreciate this fact. After he had separated Masséna from Suchet by forcing the centre of the French line, he directed his greatest efforts to the capture of Genoa. For this purpose the troops surrounding the place were increased to thirty thousand men, and were kept at or about this strength till Masséna surrendered; while on the Var the Austrian forces actively engaged during these operations numbered but twenty-five thousand. Since, at the outset, Masséna had only eighteen thousand combatants at Genoa, and since this number was rapidly reduced from day to day by casualties and sickness, it is evident that Melas could have surrounded the place and have maintained the siege there with less than thirty thousand soldiers. The increase of his troops beyond the number necessary to hold securely the place was injudicious; for the surplus could have been used with greater effect on the Var. Moreover, the surplus did not hasten the surrender of Masséna; for he was able to hold out against thirty thousand till his provisions were exhausted. Against ten thousand less he could have held out no longer. Again and again Melas assaulted the works surrounding the city, but his efforts were, to a great extent, a waste of energy; for they resulted in a greater loss to the Austrians than to the French, and had little or no effect in hastening the surrender of Masséna. In the treatment of fortresses, it is worth while to compare the methods of Bonaparte with those of Melas. In the Italian campaign of 1796-97, the strong fortresses which were held by the allies, and which were on the direct line of Bonaparte's operations, did not stop his progress for a moment. Though from a lack of siege artillery, he could not completely invest them, he pushed forward past them to decide, if possible, their fate upon the open battle-field. In that campaign he invested the fortress of Mantua, containing twelve thousand combatants, with ten thousand men; and though the besieged were finally increased to twenty thousand soldiers, he continued with ten thousand or less to hold them in check for seven months, while he won the battles of Lonato, Castiglione, Roveredo, Bassano, San Georgio, Arcole, and Rivoli. "It is upon the open field of battle," said Napoleon, "that the fate of fortresses and empires is decided."