But long before this attempt could be made the work of death had begun, and two thousand guns were raining their projectiles, charged with inevitable destruction, upon the devoted cities. They were swarming with men who had come through the interior of Russia during the night for the invasion of Europe, but there were no troops on land to oppose them, for Alan had seen that there would be no need for these. Within an hour the six cities were so many vast shambles, and still the relentless rain of death kept falling from the skies. Houses and public buildings crumbled into dust under the terrific impact of the explosions. The streets were torn up as if by earthquakes, the railways running in and out were utterly wrecked, and the victims of the pitiless attack, panic-stricken and mad with fear and agony, rushed aimlessly hither and thither through the bloody, fire-scorched streets and amidst the falling ruins until inevitable death overtook them and ended their tortures of mind and body. There was no escape even as there was no mercy. Thousands fled out into the country only to find the same rain of death falling upon the villages. It seemed as though the unclouded heavens of that May morning were raining fire and death from every point upon the devoted earth, and yet no source of destruction was to be seen. But ere long new horrors were added to the desolation which had already befallen the cities. Terrific explosions burst out high up in the air, vast dazzling masses of flame blazed out, mocking the sunlight with their brightness, and then vanishing in an instant, and after them came showers of bits of metal and ragged fragments of human bodies, all that remained of some great cruiser of the air and her crew. The Russian squadrons, numbering in all about three hundred warships, by flying several miles to the eastward and then doubling on a constantly ascending course had by this time gained a sufficient elevation to train their guns upon the Aerians, and as soon as they had done this the aerial battle became general along a curved line more than a thousand miles in length, extending from Odessa to Riga. George Cosmo had been right when he said that there would be little or no land fighting, for along that line, from the Baltic to the Black Sea, there was scarcely a man left alive by midday who was not mad with fear and horror at the frightful effects of the aerial assault. On land as well as on sea fighting was impossible. Armies and fleet could exist only in the absence of the air-ships, and they were everywhere. Cities lay utterly at their mercy, and nothing shaped by the hand of man could withstand the impact of their projectiles. But all day long the fight went on in the skies above the Russian frontier, yet not at all after the fashion imagined by the poet of the nineteenth century, who wrote, as he thought prophetically, of Airy navies grappling in the central blue.