Wireless telegraph apparatus is found installed in almost every seagoing passenger vessel of large size engaged in regular traffic, and as a means of safety as well as a convenience its usefulness has been demonstrated.  Thus on the North Atlantic the largest liners are never out of touch with land on one side of the ocean or the other, and news is supplied for daily papers which are published on shipboard.  Every ship in this part of the ocean equipped with the Marconi system, for example, is in communication on an average with four vessels supplied with instruments of the same system every twenty-four hours.  In case of danger or disaster signals going out over the sea speedily can bring succour, as clearly was demonstrated in the case of the collision between the White Star steamship Republic and the steamship Florida on January 26, 1909.  Here wireless danger messages were sent out as long as the Republic was afloat and its wireless apparatus working.  These brought aid from various steamers in the vicinity and the passengers were speedily transferred from the sinking Republic.  On April 15, 1912, the White Star liner Titanic, the largest ship afloat, sank off Newfoundland, after colliding with an iceberg.  Wireless Sos calls for help brought several steamships to the scene, and 703 persons from a total of 2,206, were rescued.  On October 9, 1913, the Uranium liner Volturno caught fire in mid-ocean, and her wireless calls brought ten steamships to her aid, which, despite a heavy sea, rescued 532 persons from a total of 657.  Again, on November 14, 1913, the Spanish steamship Balmes caught fire off Bermuda, and at her wireless call the Cunard liner Pannonia saved all of her passengers—­103.  The Titanic horror led the principal maritime nations to take immediate steps to perfect their wireless systems, and the installation of apparatus and operators soon became a prime requisite of the equipment of the world’s shipping.  Wireless telegraphy has been developed to great efficiency in all the leading navies, and powerful plants are installed on all warships.  The United States, Great Britain, and Germany, most noticeably, have established shore stations, by which they can “talk all around the world” from any ship or station.  In operation secrecy is most important.  For in the navy practically all important messages are sent in code or cipher under all conditions while in commercial work the tapping of land wires or the stealing of messages while illegal is physically possible for the evil disposed yet has never proved in practice a serious evil.  The problem of interference, however, seems to have been fairly solved by the large systems though the activity of amateurs is often a serious disturbance for government and other stations.