REPORT OF THE CHIEF OF THE WEATHER BUREAU. 



United States Department of Agriculture, 



Weather Bureau, 

 Office of the Chief, 

 Washington^ D. 6'., September ^7, 1917. 

 Sir: I have the honor to submit herewith a report of the opera- 

 tions of the Weather Bureau during the fiscal year ended June 30, 

 1917. 



Very respectfully, 



C. F. Marvin, 

 Chief of Bureau. 

 Hon. D. F. Houston, 



Secretary of Agriculture. 



In addition to the daily work of the Weather Bureau in its com- 

 prehensive and important service to the public, a prominent fea- 

 ture of the bureau's activities during the year has been the link- 

 ing of its work with the military operations of the Government 

 in the great war. This cooperation has been secured through 

 arrangements for forecasting the weather over the region of actual 

 warfare in France, the extension of aerological work to provide for 

 the making of upper air observations for the benefit of the Army 

 aviators, ballonists, and artillerists; and assistance to the Govern- 

 ment and marine interests by vessel-reporting and seacoast stations 

 and communication facilities in aid of coast patrol. 



Never in the history of conflicts of the world has the weather 

 proved such a potent factor as in the war that is now in progress 

 in Europe. This is largely due to the use of aeroplanes, dirigibles, 

 and captive balloons, to the highly perfected and powerful artillery, 

 and to the modern methods of warfare first brought into practice 

 in this conflict. Foreknowledge of existing and expected weather 

 conditions, both in the air and on the surface has, therefore, become 

 of the utmost importance. When active preparations for the mili- 

 tary preparedness of this country were begun — when the declaration 

 was made by the United States that a state of war existed with 

 the German Government — it was apparent that the Weather Bureau 

 had an important part to play. In recognition of this fact the 

 Secretary of Agriculture communicated with the Secretary of War 

 and invited attention to the service which might be rendered by the 

 Weather Bureau in furnishing the fullest possible information con- 

 cerning the meteorological conditions in the United States and adja- 

 cent regions. He also indicated the service that trained meteorolo- 

 gists could render as aids to commanders in planning military opera- 



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