Wireless stations on shore are marked by very tall masts, which support a single wire, or a set of wires, which are known as the _antenna_. The antenna has electrical capacity, and when it is connected with the other apparatus needful to produce the oscillations it disturbs the earth’s magnetic field. For temporary service, as in the case of military operations, the antenna is frequently attached to captive balloons or kites, and so suspended high in air. On ships the antenna is fastened to the masts. The step that led to this addition was taken by Count Popoff in 1895, when he attached a vertical wire to one side of the coherer of the receiver of Professor Lodge, and connected the other side with the ground. He used this to learn the approach of thunder-storms. With a knowledge of electro-magnetic waves, with a high-power oscillator, and a sensitive coherer, it remained for Marconi to connect an antenna to the transmitter, and thus secure a wide and practicable working field for the sending and receiving of his messages. This he did in 1896, and it was this addition that made the wireless telegraph of real use to men. Improvements in the transmitter and receiver have constantly increased the power of the invention, and have gradually allowed him to employ it over greater and greater distances. With Marconi’s successful demonstrations of wireless in England its use at once began. The Trinity House installed a station at the East Goodwin Lighthouse, which communicated with shore and proved of the greatest value in preventing shipwrecks. The Marconi Wireless Telegraph Company was organized in 1897, and made agreements to erect coast stations for the Italian, Canadian, and Newfoundland governments, and for Lloyd’s. The great shipping lines established wireless stations on their vessels, and the antenna were soon to be seen on points of vantage along every coast. On December 12, 1901, Marconi in Newfoundland caught the message sent from Cornwall; on January 19, 1903, President Roosevelt sent the first “official” wireless message across the Atlantic to Edward VII, and in October, 1905, a message was sent from England across the mountains, valleys and cities of Europe to the battle-ship _Renown_, stationed at the entrance to the Suez Canal. [Illustration: WIRELESS STATION IN NEW YORK CITY, SHOWING THE ANTENNA]