It is impossible to state with any accuracy how many land wireless stations there are in the world, but the list given in the _Year-Book of Wireless Telegraphy_ for 1915 enumerates about 700 stations. This list does not include private or experimental stations, and also many stations used exclusively for naval or military purposes are not given. The information available about these 700 stations is incomplete in many cases, but about 500 are controlled by various departments of the governments of the different states. Of the remainder, about 100 are controlled by the Marconi Company, the rest being in the hands of various wireless, commercial, or railway companies. Amongst the most important land stations are the Clifden and Glace Bay transatlantic stations. They are very similar in plan, and each has a separate aerial for sending and for receiving. Contrary to the usual practice, continuous current is used to charge the condensers. In Chapter IV. we saw how a current of high voltage could be obtained by connecting a number of cells in series, and at these stations the necessary high voltage is produced by connecting a number of powerful dynamos in series, on the same principle. Along with the dynamos a huge battery of accumulators, consisting of about 6000 cells, is used as a sort of reservoir of current. These stations have a normal range of considerably over 3000 miles. Last year a large transmitting station was completed at Cefndu, near Carnarvon. This station, which is probably the most powerful in existence, is intended to communicate directly with New Jersey, United States, as an alternative to the Clifden-Glace Bay route. Other powerful stations are Poldhu, in Cornwall, of which we shall speak later; the French Eiffel Tower station; the German station at Nauen, near Berlin, which last year succeeded in exchanging messages with Windhoek, German South-West Africa, a distance of nearly 6000 miles; and the extremely powerful station at Coltano, Italy. France has three stations in West Africa with a night range of 1600 miles; and Italy one in Somaliland with a normal range of about the same distance. The recently opened Chinese stations at Canton, Foochow, and Woosung have a range of 1300 miles by night, and 650 miles by day. With the fall of Tsingtau, China, Germany lost a wireless station capable of signalling over 1350 miles at night. Japan has six stations with a night range of over 1000 miles. Massawa, on the Red Sea, has a range of 1600 miles, and New Zealand has two stations with ranges of 1200 miles by day, and 2500 miles by night. Australia has a large number of stations with a normal range of about 500 miles. In the United States, which has a very large number of stations, Arlington, Virginia, covers 1000 miles, and Sayville from 600 to 2300 miles. South America has not many high-power stations, but Cerrito, in Uruguay, has a range of about 1000 miles.