The news of the organizing of a corps by the celebrated Garibaldi, had induced the Austrians to make their last demand upon Piedmont, which was a very extraordinary one, and indicated the interesting truth that they duly appreciated Garibaldi. It was, that, unless his band was immediately dispersed, they would march forward in three days. This demand was not complied with, but the King of Sardinia prepared to receive the threatened invaders. With excellent judgment, however, he did not attempt to occupy the line of the Mincio; he chose a stronger one within his own territory, and occupied that extending from Alessandria to the Apennines, toward Genoa, leaving the road to Turin open to the enemy. The Austrians moved; but, as soon as they had crossed the Ticino, the engineer who had charge of the canals which irrigate the extensive valley, was ordered to open them and make an inundation. The Austrians soon discovered that the water was rising, and the general sent word to the engineer in terms like these: "Your brother is a prisoner in my hands; if you do not immediately stop the inundation, I will cut off his head." The engineer, with the greatest resolution, pressed the work with redoubled vigor that night; and by employing two hundred more men, completed it before morning. The Austrians, finding that they were likely to be caught in a kind of trap, with the inundation rising on their right, and the Piedmontese army on their left, soon retreated, and recrossed the Ticino. THE BATTLE OF PALESTRO. This action was important, not only on account of its resulting in the first victory against the Austrians, but also because of the excellence of the Piedmontese troops, which had been denied, and was certainly seriously doubted by Louis Napoleon, who had given to Victor Emnanuel four battalions of French Zouaves for his body-guard. These were the only French troops in that battle; and they so much admired the conduct of the King of Sardinia, that they elected him "Corporal" on the field. This is esteemed the highest military honor which can be in any way acquired; and it is one which Louis Napoleon himself has never yet received, even from his own troops. The battle of Montebello was the first ever decided by a railroad. When the action commenced, there was only a single regiment to resist the Austrians. This was a French regiment, which was so soon, so rapidly, and so greatly reinforced by other French troops, transported on the railroad, that the day was soon decided in their favor. The importance and effect of this manner of conveying the troops was acknowledged by the Austrians, in their official report of the battle. THE BATTLE OF MAGENTA.