The history of the Sardinian campaign has been hitherto a history of skirmishes. The Piedmontese troops have advanced, and Radetski has retired. The Austrian position is memorable for its strength, and has been successively adopted by every defender of the Austro-Italian provinces. Peschiera, Verona, and Mantua form the three angles of an irregular triangle, of which the line of the Mincio forms the base. Charles Albert, by crossing the Mincio at Goito, is now within the triangle. The three fortresses are strong, and he has already made some attempts on Peschiera, which commands the head of the Lake of Garda. Those attempts have failed, and Verona is now his object; and there too he appears to have already undergone some failures. The true wonder is, that he has been suffered to remain a moment making these experiments, and that Austria, with 300,000 men under arms, should allow an Italian army, of 50,000 men at the most, to shut up her general, and lord it over half of her Italian territory. All this is an enigma. It is equally an enigma, that the Austrian commander-in-chief should have allowed himself to be driven out of the capital of Lombardy by the rabble of the streets, and have marched out with a garrison of 15,000 men, before a mob of half their number. He ought to have fought in Milan to his last battalion. If he had been embarrassed by orders from home, he ought to have resigned at once. A heavy blow at the insurrection in Milan would have extinguished Italian rebellion.

He has now a position in which he might fight with perfect security for his flanks and rear; with the strongest fortress in Italy, Mantua, for his place of refuge, if defeated; and, if successful, with the certainty of ruin to his adversary;—yet he stands still. It was by a brilliant movement in this position that the Austrian Kray gave the French that tremendous defeat which ultimately drove them over the Alps.

The surrounding country is of the most intricate kind—a perpetual intersection of large rivers, guarded at every passage by têtes de pont, and all the means known to military science. A war of this order may be carried on for years; and, unless the Italian population shall rise en masse, it must be a mere waste of blood and time.

The true tactique of an Italian invasion is a succession of rapid, daring, and hazardous attacks. This is the dictate of experience in every example of Italian conquest. A bold rush into the interior, leaving all fortresses behind, despising the obstacles of rivers, lakes, and mountains, and only hurrying on to meet the enemy in line, has been the principle of success from the first days of the French assaults on Italy to the last. Their war was an incursion, their marches were a headlong charge, their battles were outbursts of furious force; and, if their triumphs were transient, they failed merely from the national caprice which tires of every thing, and from the exhaustion of an ill-regulated finance. The French, even under the old Bourbons, never descended the Alps without sweeping all resistance before them. The campaigns of Napoleon in 1796, and the following year, were on the same principle. He plunged into Italy at the head of 50,000 troops, ragged, hungry, and in beggary, but the first robbers in Europe. He told them that, by beating the Italians, they should get clothes, food, and money. As a strategist, he probably committed a thousand faults, but he did not commit the grand fault of all, that of giving the enemy time to recover his senses. He fought every day,—he fought by night as well as by day. At Montenotte, he fought for twelve hours, and was beaten; he again mounted his horse at midnight, attacked the victor in his first sleep, and, before morning, was master of the mountains, with the Austrian army in full flight, and the gates of Turin open before him. The Russian campaign in Italy was on the same principle. "When you are not fighting, march; when you are not marching, fight." When the Austrian generals advised Suwarrow to manœuvre, he laughed, and told them that tactics were only trifling. "Make reconnoissances," said the greybeard pupils of the Aulic Council. "My reconnoissances," said the great Russian, "are of 10,000 men. Form column, charge bayonet, plunge into the enemy's centre. These are my only reconnoissances." In three months he drove the French, under their two best officers, Macdonald and Moreau, across the Alps, and cleared Italy. A lingering Italian campaign is always a campaign thrown away, or a country lost. It is the work of a military gambler. Napoleon's invasion of Italy, in his consulate, was one of the most desperate hazards ever ventured in war. He might have been defeated, and, if defeated, he must have been utterly ruined. But he attacked the Austrians, was repulsed, renewed the attack in desperation, repulsed the enemy in turn, and next day saw all Italy capitulate to him.

What a month may bring forth is beyond our calculation; but while we were writing those pages, there had been a general movement of the Piedmontese troops on Verona, probably with the intention of aiding some insurrectionary movement in the city. The Piedmontese artillery speedily demolished the field-works in the approaches to the city. A general advance was ordered, and the Austrian troops continued to retreat, still turning on the advancing line, and fighting, through a country the greater part of which is a low shrubby forest. At length, however, a Piedmontese division was vigorously attacked, taken by surprise, and broken with a loss so heavy, as to determine the retreat of the army to its position of the morning. Still, this was but an affair of posts; and, in the mean time, General Nugent, with an army of 30,000 men, is putting down the insurgents in the Venetian provinces, and is marching towards the flank of the Piedmontese.

One fact is evident, that Italy has not risen in a body, and that, with all the harangues of her revolutionary orators, and all the promises of what those orators call "her heroic youth, burning to extinguish the abomination of the Teutons," very few of them have stirred from their coffee-houses. Italy, with her twenty millions of men, has probably not furnished to the field twenty thousand volunteers. Yet this is the time for which they have been all panting in all kinds of sonnets; when the "new spirit of political regeneration" has full range for its flight, when the Austrian police are a dead letter, and when Spielberg and its bastions are a bugbear no more.

But the movements of the Roman populace are matters of more rapid execution. What the Pope was a month since, every one knows;—Pius the powerful, Pius the popular, Pius the restorer of liberty to all the aggrieved nations of Italy, with a slight appendix, including the aggrieved nations of Europe. But the populace, which gave him his titles, have now changed them, and he is "Pius the Monk."

In a year whose every week produces a revolution, who can predict the events of a month? In the middle of this month of May, Pope Pius is virtually a prisoner in his palace; within a week he may be transferred to the castle of St Angelo; within a fortnight he may be an exile, an outlaw, or a refugee in England.

The intelligence from Rome at the commencement of the month was simply, that he was a cipher. The people, in their eagerness for Austrian overthrow, demanded a declaration of war. But the German bishops are said to have informed the Court of Cardinals, that a measure of that order would instantly produce a renouncement of their allegiance to the Roman See. A council of cardinals was now summoned, before whom the Pope laid a recapitulation of his policy, which may be considered in the light of a penitential speech. In the mean time, all his ministers tendered their resignations, probably hoping to lay the onus of things on the shoulders of Pius himself, and glad to escape from being massacred by the mob, or hanged by the Austrians.

But the Pope wisely determined, that whatever happened to one, should happen to all, and refused to let them resign. The general staff then held a "sitting," and the municipality marched in procession, to give their opinion at the Vatican on matters of government, and recommend "abdication!" Such are the benefits of telling the rabble that they are the true depositaries of the national wisdom. In other and better days, the Pope would have sent those volunteer privy-councillors to the galleys, as their impudence richly deserved. But he may now thank his own political visions.