The History of the Great War (Complete 6 Volume Edition). Arthur Conan Doyle

German line. To the admirable aeroplanes was given the task of solving the mystery, and regardless of gun-fire or hostile craft they quartered the whole country round until at last, by a combination of luck and skill, they concluded that a Belgian barn, five miles behind the enemy line and fifteen from Poperinghe, was the lair of the monster. A large British gun came stealthily up and lay concealed till dawn when it opened upon the barn. The third or fourth shell went home, a magazine exploded, the barn went up, and there was peace henceforth in Poperinghe.