The most important development in marine meteorology in recent years has been the rapidly increasing use of radiotelegraphy, both by marine observers in transmitting reports of observations to shore and to other ships, and by meteorological institutions in issuing weather bulletins and storm warnings to vessels at sea. The first regular undertaking in this line was carried out under the auspices of the London _Daily Telegraph_ in the year 1904. This newspaper arranged with some of the leading transatlantic steamship lines to furnish weather reports by wireless from their vessels, and these reports were published in its columns for several months. The following year the United States Weather Bureau began, in a tentative way, the collection of wireless weather reports from off-shore vessels, and similar undertakings were soon afterward launched in other parts of the world, but for some years such reports were of little practical value, owing to the limited range of wireless communication. [Illustration: A SHIPBOARD WEATHER MAP Vessels off the American coast can make their own weather maps every night, using data supplied at fixed hours by high-power radio stations (shown by stars on the map), together with radio reports from other vessels. Letters near stations are the code letters used in wireless bulletins to describe the stations. Vessel reports are indicated by names. Arrows show direction of wind and the force on the Beaufort scale (shown by the number of feathers). Besides data for constructing maps, the radio stations issue forecasts and storm reports for each of the numbered zones shown off the Atlantic coast and over the Gulf.] At the present time wireless reports from ships on the Atlantic enable the forecasters on both sides of that ocean to extend the areas of the weather maps on which their predictions are based, and reports from ships are also received to a limited extent by forecasters on our Pacific coast as well as in the Far East, India, and elsewhere. In this country such reports have been especially valuable in indicating the movements of West India hurricanes, and thus have helped to solve the problem of protecting the vast tonnage that has been attracted to Caribbean waters by the opening of the Panama Canal. The reciprocal process of transmitting weather intelligence to vessels by wireless bulletins, broadcasted at certain hours every day by high-powered radio stations, has made much more progress. Such bulletins include information concerning the current and prospective weather, winds and storms over specified ocean areas, as well as reports of observations made at a number of land stations, from which it is possible for vessels at sea to construct their own weather maps. They are thus enabled to take advantage of favorable winds and to avoid unfavorable winds and storms. Wireless weather reports from other vessels help to piece out these shipboard maps.