in the military occurred during the American Civil War with the Union Army Balloon Corps established in 1861. During the Paraguayan War (1864–70), observation balloons were used by the Brazilian Army. Balloons were used by the British Royal Engineers in 1885 for reconnaissance and observation purposes during the Bechuanaland Expedition and the Sudan Expedition. Although experiments in Britain had been conducted as early as 1863, a School of Ballooning was not established at Chatham, Medway, Kent until 1888. During the Anglo-Boer War (1899–1902), use was made of observation balloons. A balloon was kept inflated for 22 days and marched 165 miles into the Transvaal with the British forces. Hydrogen-filled balloons were widely used during World War I (1914–1918) to detect enemy troop movements and to direct artillery fire. Observers phoned their reports to officers on the ground who then relayed the information to those who needed it. Balloons were frequently targets of opposing aircraft. Planes assigned to attack enemy balloons were often equipped with incendiary bullets, for the purpose of igniting the hydrogen. The Aeronaut Badge was established by the United States Army in World War I to denote service members who were qualified balloon pilots. Observation balloons were retained well after the Great War, being used in the Russo-Finnish Wars, the Winter War of 1939–40, and the Continuation War of 1941–45. During World War II the Japanese launched thousands of hydrogen "fire balloons" against the United States and Canada. In Operation Outward the British used balloons to carry incendiaries to Nazi Germany. During 2018, incendiary balloons and kites were launched from Gaza at Israel, burning some 12,000 dunams (3,000 acres) in Israel. Large helium balloons are used by the South Korean government and private activists advocating freedom in North Korea. They float hundreds of kilometers across the border carrying news from the outside world, illegal radios, foreign currency and gifts of personal hygiene supplies. A North Korean military official has described it as "psychological warfare" and threatened to attack South Korea if their release continued. Hot air returns Ed Yost redesigned the hot air balloon in the late 1950s using rip-stop nylon fabrics and high-powered propane burners to create the modern hot air balloon. His first flight of such a balloon, lasting 25 minutes and covering 3 miles (5 km), occurred on 22 October 1960 in Bruning, Nebraska. Yost's improved design for hot air balloons triggered the modern sport