“We take the left wing in Belgium.”

It was an admission of failure; it was the acceptance of a new situation. In the original scheme for world warfare that the Lord Paramount had laid before the Council of the British Empire, he had dismissed the possibility of fighting in western Europe. He had seen his war east of the Vistula and Danube and with its main field in Asia. He had trusted unduly to the wisdom and breadth of view of both America and the European chancelleries. And consequently, in spite of a certain insistence from Gerson, he had troubled very little about the novel possibilities of air war at home. Now, hard upon the heels of the naval tragedy, came the new war in the air.

The land war on the European frontiers made little progress after the first French advance into Westphalia. The Franco–Italian front was strongly fortified on either side, and the numerous and varied mechanisms of the reconstituted British army had still to come into action. There had been some miscalculation about the transport needed to put them across the Channel. But every power now possessed huge air forces, and there was nothing to prevent their coming into action forthwith. The bombing of London, Paris, Hamburg, and Berlin with high explosives occurred almost simultaneously. The moon was just entering upon its second quarter; the weather all over the Northern Hemisphere was warm and serene, and everything favoured this offensive.

Night after night, for fifteen days, the air of Europe was filled with the whir of gigantic engines and the expectation of bursting bombs. The fighting planes kept each other busy; anti-aircraft guns were a disappointment, and all the great centres of population seethed with apprehensions and nervous distresses that might at any time explode in senseless panics. The early raiders used only high explosives. The conventions were observed. But everywhere there was a feeling that these explosive and incendiary raids were merely experimental preludes to the dreaded gas attacks.

There was a press agitation in London for “Gas masks for everyone” and a strong discussion of the possibilities of the use of “anti-gases.” The London authorities issued exhortations to the people to keep calm, and all theatres, music halls, and cinemas were closed to prevent nocturnal congestions of the central districts. Millions of masks were issued, most of them of very slight efficiency, but they served to allay panic, and indeed no alleged precaution was too absurd for that purpose.

Gerson, looking ahead, removed as much as he could of the establishment of the government headquarters to a series of great gas-proof dugouts he had prepared at Barnet, but for a time the Master clu............