1. The ‘Paris Gun’, as it was properly known (although later confused with the gun known as ‘Big Bertha’), was a combination of a 15-inch gun and an 8.2-inch gun, with two extensions to the barrel, each some forty feet long. To support its enormous weight, it was fixed to an overhead gantry with a pulley mechanism. The maximum range of the Paris Gun was roughly eighty miles, and to propel a shell of 280 pounds across such a distance it required a charge of almost twice as much explosive. There were three such weapons, in scattered emplacements near Laon in the forest of St Gobain. One burst its breech after firing two shots on 25 March; the third came into action on the 29th.

1. Von Kuhl wrote nine years later: ‘Such a dispersal of the Armies in three directions was thinkable only when, as Ludendorff said, a great victory had been achieved – that is, when the enemy had been beaten on the whole front … The situation was considerably different … thus there was a complete change of plan. Hitherto the main feature had been the attack of the Second and Seventeenth Armies against the British. To the Eighteenth Army fell only the protection of attack from the French. Now the French and British were to be separated and both attacked simultaneously. This meant shifting the attack a good way to the left.’