While Italy struck the first blow on land, the first offensive operation of the Italo-Austrian conflict by sea came from Austria. This was an extensive raid on Italy's Adriatic coast. Its object was to delay the Italian concentration by attacking vital points on the littoral railway from Brindisi to the north. [Illustration: The Coasts of Italy and Austria, Showing the Naval Raid May, 1915.] The Austrian fleet began its attack early on the morning of Monday, May 24, 1915. The ships engaged were a squadron from Pola, consisting of two battleships, four cruisers, and eighteen destroyers, strongly supported by aircraft. The assault extended from Brindisi to Venice, and covered a large extent of coast territory hard to defend. At Venice the Austrian air raiders dropped bombs into the arsenal and the oil tanks and balloon sheds on the Lido. The priceless relics of art and architecture, all that remained to recall the city's proud position as ruler of the Adriatic, were uninjured, but the attack from the air caused an outcry from the nations of the Entente almost equal to that which rang through the world when the Germans shelled the cathedral at Rheims and destroyed Louvain. The Austrians replied that the attack was a serious military operation, and by no means the wanton outrage their enemies had tried to make it appear. The Austrian naval raid lasted barely two hours, but in that time the cruiser _Novara_ and several destroyers attacked Porto Corsini, north of Ravenna, in a vain effort to destroy the Italian torpedo base; the cruiser _St. Georg_ shelled the railway station and bridges at Rimini; the battleship _Zrinyi_ attacked Sinigaglia, and wrecked the railway station and bridge; south of Ancona the battleship _Radetzky_ destroyed a bridge over the River Potenza. In the south the cruisers _Helgoland_ and _Admiral Spaun_ with destroyers shelled a railway bridge and station and several signal stations in the neighborhood of Manfredonia and Viesti, and caused some damage in small coast towns. The raid was well planned and swiftly executed, and it accomplished much of its purpose. The Italian fleet was taken by surprise, and the marauders were back in safety at Pola by six o'clock in the morning, unharmed.