REPORT OF THE SECRETARY. 183 



increases have been made gradually until at present there are about 

 425 river and 25 rainfall stations distributed along all except the 

 very smallest rivers of the United States. 



The river forecasts issued daily by the Weather Bureau have 

 contributed in no small measure to the success of navigation in the 

 great inland waterways of the countr3\ Flood warnings are issued 

 whenever necessary, giving specific information as to the time of 

 arrival of floods, the highest stages expected, and the duration of 

 the floods. This information is of the greatest value to agriculture 

 and many other interests. 



Previous to 1897 the forecasts rarely attempted to indicate the 

 exact heights that tlfe floods would attain, but study and investiga- 

 tion have resulted in constant improvement until exact flood fore- 

 casts can now be made for periods from one day to four weeks in 

 advance. For several years the river and flood service has been 

 engaged in the preparation of forecast schemes for all the principal 

 river systems — in other words, in developing rules applicable to fore- 

 casting in each of the rivers, and making a permanent record of these 

 rules for future use. Schemes of this character have already been 

 completed for the Ohio River and its tributaries, and the study of 

 the Mississippi River is now under way. 



During the Mississippi flood of 1897 property to the value of 

 about $15,000,000 was saved through the Weather Bureau flood 

 warnings, and as much during the flood of 1903, while during the 

 great flood of 1912 a saving exceeding $16,000,000 was reported. 

 During a single flood in the Sacramento Valley of California in 1909 

 property to the value of $300,000 was saved through the warnings 

 of the Weather Bureau, and similar instances are matters of frequent 

 record. The work has kept pace with the development of the 

 country, and its usefulness is limited only by the amount of money 

 that Congress is willing to provide for its maintenance. 



MARINE METEOROLOGICAL. CHARTS. 



Upon the recommendation of the Board on Wireless Telegraphy in 

 July, 1904, and approved by the President, the ocean meteorological 

 work and the collection of observations from vessels at sea, formerly 

 under the Hydrographic Office, Navy Department, was transferred 

 to the Weather Bureau. At that time 570 vessels of all nationalities 

 were taking observations and rendering monthly reports. The 

 number cooperating with the Weather Bureau on July 1, 1912, was 

 2,291. 



The observations thus collected are used in the preparation of 

 marine meteorological charts of the oceans and the Great Lakes. 

 These charts are given fi-ee issue to vessel captains, marine interests, 



