74 ANNUAL EEPOETS OF DEPAETMENT OF AGEICULTUEE. 



series of observations to greater altitudes. This was accomplished 

 by means of sounding balloons on July 17 and 18, 1914, at Fort 

 Omaha, Nebr. The observations are not yet completely reduced or 

 pubhshed. 



Pyrhehometric observations at great altitudes were made in coop- 

 eration with the Smithsonian Institution during July, 1914, at Fort 

 Omaha. Three automatically recording pyrheliometers, devised and 

 caHbrated by the Astrophysical Observatory of the Smithsonian 

 Institution, were carried up by means of free air balloons. Balloon 

 meteorographs were sent up within an hour or two of the time of the 

 pyrheliometers' ascent. An excellent pyrhehometric record was 

 obtained at a height of 25 kilometers. The complete data are not 

 yet published, but a prehminary statement may be found in a recent 

 report on Field Work of the Smithsonian Institution. 



Kite flying from the deck of the United States Coast Guard cutter 

 Seneca was undertaken during her May and June cruises into the 

 ice fields of the North Atlantic; 12 observations by means of the kites 

 were made during the May cruise and 16 during the June cruise. 

 In addition to these observations, recording meteorological instru- 

 ments were exposed on the deck of the Seneca, and sea-water tem- 

 peratures were obtained. These observations will be reduced and 

 pubhshed in the Monthly Weather Review, 



In the transfer of the aerological work to the Middle West end to 

 the central office at Washmgton, D. C, considerable progress has 

 been made. It is expected that observations will begin during the 

 fall of 1915. 



Meteoes. — ^Meteors often become luminous in the very highest 

 regions of the earth's atmosphere of which we have any knowledge, 

 and the careful and systematic study of meteoric appearances 

 seems to be at the present time the only means we have of gaining 

 information of this region of the atmosphere, which is almost be- 

 yond the reach of any other means of investigation. It is hoped 

 that with the development of the aerological work, this line of study 

 may also receive its appropriate attention. 



SOLAR RADIATION INVESTIGATIONS. 



The standardization of CaUendar pyrhehometers effected at Mount 

 Weather in 1913-14 has made possible the reduction to heat units of 

 records obtained at Washington by means of one of these instruments 

 between July, 1909, and April, 1912. These data have been utilized 

 to determine for Washington the diurnal and the annual variations 

 in the hourly and daily amounts of solar and sky radiation. The 

 results are pubhshed in the Monthly Weather Review for March, 1915, 

 and the daily totals and departures from the normal have since been 

 published monthly in the Review. 



At the end of September, 1914, observations of the intensity of 

 solar and sky radiation were discontinued at Mount Weather, Va. 

 Before the end of the following month most of the radiation apnaratus 

 had been transferred to Washington and installed in the (Joilege of 

 History building, American University, which affords excellent 

 exposures for both the CaUendar and the Marvin pyrhehometers. 



