WEATHER BUREAU. 123 



ernment departments but from commercial aviation concerns as well. 

 In many cases reprints of special discussions and summaries were 

 issued in answer to these requests. 



Work has been continued on the preparation of a summary en- 

 titled "An Aerological Survey of the United States." A'N^ien com- 

 pleted, this will contain the results of all free-air observations made 

 in this country. 



The publication of monthly summaries of free-air conditions in 

 current issues of the Monthly Weather Review was begun in January, 

 1922, and has been continued. 



During the year there was brought to completion an exhaustive 

 study of the relations existing between surface winds and tempera- 

 tures on the one hand, and free-air pressures on the other, the pur- 

 pose being to make possible the construction of pressure maps for 

 upper levels for use in forecasting. This has been published as 

 Supplement No. 21, entitled " The Preparation and Significance of 

 Free- Air Pressure Maps for the Central and Eastern United States.'^ 

 A preliminary application has yielded encouraging results, and it 

 is believed that with further extension of the study important and 

 valuable aids to forecasters will be provided. 



CLIMATOLOGICAL DIVISION. 



METEOROLOGICAL REPORTS. 



The work of checking receipt of and the examination of meteoro- 

 logical forms from all classes of stations, the preparation of letters 

 correcting errors discovered in these reports, their filing, and final 

 assemblage and binding for preservation have gone forward promptly, 

 and the several processes of accomplishing these are as near up to- 

 date as feasible. 



PUBLICATIONS. 



The Annual Report of the Chief of Bureau, 1921-22, was prepared 

 and printed as usual, and special effort was made to make the chap- 

 ters on windstorms, hail, etc., as complete as possible. 



The summaries of climatological data from the various States were 

 published without material change from the style last adopted. A 

 useful feature of the climatological data for the California section, 

 was provided for in the form of an annual summary showing by 

 months and for the season the precipitation for that section during^ 

 the rainfall season 1921-22 — that is, from Julv 1 to June 30 — instead 

 of for the calendar year. This summary is issued as promptly as- 

 possible after July 1, and gives to those interested in the seasonal 

 distribution of precipitation in that State the earliest possible facts.. 

 The publication has been well received by the water interests of th& 

 State and may be extended, if found desirable, into other Pacifia 

 States where precipitation conditions are similar to those of Cali- 

 fornia. 



A special effort was made at the close of 1922 to have printed for 

 each of the regular stations an annual summary of station weather 

 data for that year, together with tables of monthly and annual means 

 of temperature and monthly and annual totals of precipitation, for 

 the entire period of observations at the respective stations, as these 

 data, particularly those of the monthly and annual temperatures^ 



