WEATHER BUREAU. 165 



representative of the different climatological sections of the United 

 States. Prof. H. H. Kimball will have charge of the carrying on of 

 these observations, mostly at points west of the Mississippi River, 

 during the coming fiscal year. Preparations are practicall}' com- 

 pleted for equipping these stations with the new form of pyrhelio- 

 meter developed and partly constructed by Prof. C. F. Marvin. It is 

 hoped to supplement this instrument in the near future with one that 

 records continuously. 



THE VAPOR IN THE ATMOSPHERE. 



Progress has been made toward the installation of apparatus, 

 especially optical, adapted to the study of the quantity of the water 

 vapor in the atmosphere and the investigation of the radiation and 

 absorption of materials and their varying surfaces. 



The amount of water vapor in the atmosphere is of such importance 

 as to justify attempts by all known methods to determine it. At 

 present only the hair hygrometer and the spectroscope are available 

 for measurements in the atmosphere above the surface of the earth, 

 and while both methods are unsatisfactory, they should be used for 

 such results as they can give. The amount of water vapor in the air 

 next to the earth's surface is so strongly affected by purely local 

 conditions that its use in weather forecasting has long since been 

 abandoned. 



The spectroscopic observations will be made by Prof. William J. 

 Humphreys. 



DISCUSSION AND PUBLICATION OF DATA. 



In meteorology, as also in most other natural sciences, the accumu- 

 lation of data and their discussion from a physical standpoint must 

 go hand in hand; in other words, it would not be wise to go on accu- 

 mulating data without an attempt at interpretation. To provide 

 a means of publishing the data obtained at the Mount Weather Re- 

 search Observatory a regular publication, known as the bulletin of 

 that observatorv, was established in 1908, as noted in former annual 

 reports. On account of his experience and success as editor of the 

 Monthly Weather Review, Prof. Cleveland Abbe has been assigned 

 as editor of the bulletin. 



The field of the new bulletin is technical meteorology and not 

 climatology or education. During the year six numbers have ap- 

 peared, completing Volume II and including the first part of Vol- 

 ume III. The bulletin contains the detailed records brought down 

 by kites or balloons up to about 5.000 meters in the atmosphere. The 

 results of the first series of synchronous sounding-balloon records 

 made in this country will appear in part 2 of Volume III. 



During the year articles discussing the theoretical as well as the 

 practical application of the data obtained at Mount Weather and 

 elsewhere to the problems of meteorology' have appeared in the bulle- 

 tin. The articles on aerial work have been contributed by Research 

 Director Blair; those on the quantity of heat received from the sun 

 by Prof. H. H. Kimball ; and those on the changes of wind with alti- 

 tude bj' Prof. A. J. Henry, who has also served as executive otKcer of 

 the observatory. 



