Eiffel Tower In 1909, a permanent underground radio centre was built near the south pillar, which still exists today. On 20 November 1913, the Paris Observatory, using the Eiffel Tower as an aerial, exchanged wireless signals with the United States Naval Observatory, which used an aerial in Arlington, Virginia. The object of the transmissions was to measure the difference in longitude between Paris and Washington, D.C. Today, radio and digital television signals are transmitted from the Eiffel Tower. A television antenna was first installed on the tower in 1957, increasing its height by 18.7 m (61.4 ft). Work carried out in 2000
Eiffel Tower first level. The layout of both first and second levels was modified, with the space available for visitors on the second level. The original lift in the south pillar was removed 13 years later. On 19 October 1901, Alberto Santos-Dumont, flying his No.6 airship, won a 100,000-franc prize offered by Henri Deutsch de la Meurthe for the first person to make a flight from St. Cloud to the Eiffel Tower and back in less than half an hour. Many innovations took place at the Eiffel Tower in the early 20th century. In 1910, Father Theodor Wulf measured radiant energy at