OF THE UNITED STATES ARMY 149 



caster at Washington has the variovis charts before him showing 

 wipd and weather conditions prevaiHng over the United States 

 within an hour and a half after the observations are made. From 

 these charts he prepares the forecast of weather conditions for the 

 various sections of the United States and at the same time prepares 

 a statement of the wind and weather conditions at various altitudes 

 along the various air routes for the use of aerial navigation. This 

 service is already being used by the aerial mail service, and it is also 

 used by the military flyers, as is evidenced by telegraphic requests 

 received at various military meteorological stations for special re- 

 ports on the weather and wind conditions when long distance flights 

 are contemplated. 



The problem of exploring the upper air currents over the At- 

 lantic was at first thought insoluble on account of the absence of 

 fixed bases, but the success of the Meteorological Service in devel- 

 oping its long-range propaganda balloons has now made possible 

 the mapping of the upper-air highways across the Atlantic, for ar- 

 rangements are being made to send up both from coastal stations 

 and from trans-Atlantic steamers these long-range balloons designed 

 now for from two to three thousand mile flights, and adjusted to 

 maintain a constant altitude and to drop in western Europe their 

 records of average winds in these heretofore unchartable regions. 

 The importance of this work for the future of aviation needs no 

 emphasis. 



The success which the Meteorological Service has attained would 



have been wholly impossible had it not been for the intimate and 



effective cooperation which has been extended to it in all of its 



projects by Director Marvin and the whole staff of the United States 



Weather Bureau. The chief credit for the work abroad should 



go to Major William R. Blair, commissioned from the Weather 



Bureau for the observational work with the A. E. F. For the 



success of the service in this country Captain Sherry and Lieutenant 



Waterman have perhaps the chief responsibility. Captain Murphy 



and Professor Fassig have, however, contributed very important 



elements. 



University of Chicago, 

 April, 1919. 



