As existing submarine cable operators in the early 1900s had held a monopoly on international telegraph service to Newfoundland, Marconi's first regular transatlantic wireless service was established on October 17, 1907 between Derrygimla Bog, Clifden, Galway, Ireland and Glace Bay, Nova Scotia. An additional Marconi receiving station in Letterfrack, Ireland operated briefly from 1913 until 1917. Due to destruction caused by the Irish Civil War in 1922, traffic formerly carried at Clifden was permanently redirected via Marconi's new station at Ongar in Essex, a link which remained in service until replaced by the Canadian shortwave beam circuit in October 1926. On June 15, 1919, the first non-stop transatlantic aeroplane crossing by Capt. John Alcock and Lt. Arthur Brown left Newfoundland and made an unplanned landing at the Marconi site in Clifden, Ireland. Despite references in several publications, Ballybunion Station was not built by Marconi, and never operated commercially. The station was built by the Universal Radio Syndicate. Construction started in 1912, but the station had not obtained a commercial licence by the time World War 1 started. The company went into liquidation in 1915. A sister station at Newcastle New Brunswick, built to the same design as Ballybunion, suffered a similar fate. The Marconi Company bought the two stations from the liquidator in 1919, mainly to prevent their use by potential competitors. The stations were not idle in the interim, however, having been appropriated by the British Admiralty almost immediately upon outbreak of the Great War and kept in constant activity as key components of the allied communication system until the Armistice of November 1918. The Marconi Company did not use the stations commercially, and it would appear that the Ballybunion station was only used briefly, in March 1919 for a successful telephony experiment with the Marconi station in Louisbourg, and for communication with the R34 airship in July 1919. In March 1919, Marconi engineers H.J Round and W.T. Ditcham made the first east-west transatlantic broadcast of voice, using valve technology, from the Ballybunion station using the callsign"YXQ". The first west to east voice transmission had already been achieved by Bell Systems engineers from the US Navy station at Arlington Virginia to the Eiffel Tower in October 1915. The contents of Clifden and Ballybunion were sold for scrap to a Sheffield-based scrap merchant, Thos. W. Ward in 1925.