At least that was the theory. Putting it into practice became a year-long challenge for a young British scientist, William Lawrence Bragg. Before the war, he and his father, William Henry Bragg, had used a beam of X-rays to discover the highly ordered arrangement of atoms in a crystal. Those X-rays are type of electromagnetic radiation.But at the start of World War I, the young Bragg was out of his element. He had been placed in a British regiment that rode horses into battle, even though he knew little about riding.In July 1915, Hedley pulled Bragg, 25, out of the Royal Horse Artillery. Hedley asked him to work on the sound-ranging project. “To have a job where my science was of use … seemed too good to be true,” Bragg later wrote in his autobiography. That same summer, he traveled to the Vosges (Vozh) Mountains of France. There, the scientist examined first-hand the experimental sound-ranging equipment developed by the French. While in France, Bragg also learned that his younger brother, Bob, had died of wounds suffered during combat in Gallipoli (Guh-LIP-oh-lee), Turkey. Still in mourning, Bragg went to Paris to gather electrical supplies for the first sound-ranging station. It would be set up at Kemmel Hill, south of the village of Ypres (EE-pruh), in neighboring Belgium. That area would see some of the worst fighting in this war.