Another valuable use of wireless is in carrying on the work of lighthouses and lightships during snowstorms or dense fogs, which the light cannot penetrate. So far not much has been done in this direction, but the French Government have decided to establish wireless lighthouses on the islands outside the port of Brest, and also at Havre. Automatic transmitting apparatus will be used, sending out signals every few seconds, and working for periods of about thirty hours without attention. The improvement in the conditions of ocean travel wrought by wireless telegraphy is very remarkable. The days when a vessel, on passing out of sight of land, entered upon a period of utter isolation, is gone for ever. Unless it strays far from all recognized trade routes, a ship fitted with a wireless installation is never isolated; and with the rapidly increasing number of high-power stations both on land and sea, it soon will be almost impossible for a vessel to find a stretch of ocean beyond the reach of wave-borne messages. The North Atlantic Ocean is specially remarkable for perfection of wireless communication. For the first 250 miles or so after leaving British shores, liners are within reach of various coast stations, and beyond this Poldhu takes up the work and maintains communication up to about mid-Atlantic. On passing beyond the reach of Poldhu, liners come within range of other Marconi stations at Cape Cod, Massachusetts, and Cape Race, Newfoundland, so that absolutely uninterrupted communication is maintained throughout the voyage. On many liners a small newspaper is published daily, in which are given brief accounts of the most striking events of the previous day, together with Stock Exchange quotations and market prices. This press news is sent out during the night from Poldhu and Cape Cod. During the whole voyage messages may be transmitted from ship to shore, or from shore to ship, with no more difficulty, as far as the public are concerned, than in sending an ordinary inland telegram. The transmitting ranges of ship installations vary greatly, the range of the average ocean liner being about 250 miles. Small ships come as low as 50 miles, while a few exceptional vessels have night ranges up to 1200 or even 2500 miles. Although an outward-bound vessel is almost always within range of some high-power shore station, it is evident that it soon must reach a point beyond which it is unable to communicate directly with the shore. This difficulty is overcome by a system of relaying from ship to ship. The vessel wishing to speak with the shore hands on its message to some other vessel nearer to land or with a longer range, and this ship sends forward the message to a shore station if one is within its reach, and if not to a third vessel, which completes the transmission.