A Siren

Collier's New Encyclopedia (1921)

USED TO WARN OF ENEMY AIR RAIDS warnings might prompt the population to seek shelter. Bells and whistles were used for the same purpose. Underground passages were constructed at various points, to which the people flocked when the alarm was given. By these measures of precaution the casualties were sensibly lessened. The Allies for a long time were un- A ZEPPELIN DIRIGIBLE AIRSHIP willing to retaliate in kind. But later, as in the case of asphyxiating gases, they were forced in self-defense to adopt the same methods as the enemy, although they never attacked hospitals, as the Germans did repeatedly through the war. It was some time however before the bombing operations of the Allies rivaled those of Germany in effectiveness. The latter had organized organized their service to a high point of efficiency. They employed two types of planes, triplanes equipped with machine guns and automatic bomb throwers; the Gothas with two Mercedes engines of 260 horse power each and carrying 1,200 pounds of explosives, with gasoline sufficient for a five hours' flight, and the Friedrichshafens, with two Benz motors of 225 horse power each and carrying half a ton of bombs and gasoline supplies for four hours. By the summer of 1918, the Allies had perfected bombing planes that rivaled those of the Germans in size and power and greatly exceeded them in number. They then began a system of reprisals over the cities of the Rhine valleys, selecting as their targets munition factories, railway sidings, barracks, and steel works. Despite their efforts to limit their targets, much damage was done inevitably to civilian property and considerable loss of life resulted in Coblenz, Düsseldorf, Cologne, and other cities. In a three months ' airplanes period, 249 raids were made and 247 tered tons of bombs dropped. So heavy was of A FRENCH ELECTRIC SIREN USED TO GIVE THE the damage inflicted that the German Government on Nov. 4 appealed to the American Government, and proposed the abandonment by both sides of attacks