The practical value of these charts, of which 200,000 copies were distributed to the masters of merchant vessels of all nationalities, was promptly recognized. By taking advantage of the favorable winds and currents shown on the charts, and avoiding those that were unfavorable, mariners were able to reduce the average time of a sailing voyage between the Atlantic and Pacific ports of the United States by forty days. The money value of the charts to vessels sailing from the United States to South America and the Far East was estimated at $2,250,000 per annum. British shipping on all seas is said to have benefited to the extent of $10,000,000 per annum. Neither was the utility of the charts limited to the saving of money. The following episode is cited in Maury’s biography: “When the _San Francisco_, with hundreds of United States troops on board, foundered in an Atlantic hurricane, and the rumor reached port that she was in need of help, everyone looked to Maury as the only man in the country who could tell where to find the drifting wreck. To him the Secretary of the Navy sent for information. He at once set to work and showed how the wind and currents acting upon a helpless wreck would combine to drift her ‘just here’, pointing to a spot on the chart, and making a cross mark with the blue pencil he had in his hand. Just there the relief was sent, and just there the survivors of the wreck were picked up. This was an incidental result of his study of winds and currents.” A further outcome of Maury’s enterprise was the holding, at his suggestion, and by invitation of the United States Government, of an International Maritime Conference, which met in Brussels in 1853, and worked out a world-wide plan for meteorological observations at sea. The work thus begun has since been carried on by the leading maritime nations of the world. In the United States the duty of gathering weather reports on a uniform plan from vessel masters has been intrusted, at different times, to the Hydrographic Office, the Signal Service, and the Weather Bureau. It is now performed by the last-named institution, through its Marine Division, but the Pilot Charts and books of sailing directions (“Pilots”) in which the compiled information is published, are issued by the Hydrographic Office of the Navy. The modern successors of Maury’s Wind and Current Charts are, especially, the Pilot Charts for the different oceans issued monthly in Washington, and the monthly charts of similar character published by the British and German governments. Apart from these periodical publications, valuable collections of meteorological charts for oceans or smaller marine areas have been published by the British, German, Dutch, Indian, Japanese and other authorities.